Methods of intracerebral implant delivery

ABSTRACT

The method of delivering an implant in an intracranial vessel includes deploying an anchor of a tethering device in an anchoring vessel forming a first fixation point and advancing a guide-sheath to a location near the anchoring vessel. The tethering device has a tether extending proximally from the anchor and the guide-sheath has at least one lumen. The method includes attaching the guide-sheath to the tether of the tethering device forming a second fixation point proximal to the first fixation point, delivering an implant through the lumen of the guide-sheath towards a treatment site distal to the first fixation point and located within an intracranial vessel, and deploying the implant at the treatment site. Related devices, systems, and methods are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage entry, filed under 35 U.S.C. § 371,of International Application No. PCT/US2016/043742, filed on Jul. 22,2016, and claims priority to U.S. Provisional Application Nos.62/196,613, filed Jul. 24, 2015, entitled “Anchoring Guide System;” and62/275,963, filed Jan. 7, 2016, entitled “Method of IntracerebralImplant Delivery;” and 62/275,939, filed Jan. 7, 2016, entitled“Anchoring Delivery system;” and 62/301,857, filed Mar. 1, 2016,entitled “Anchoring Delivery System.” Priority to the aforementionedfiling date is claimed and the entire contents of each are herebyincorporated by reference herein in their entireties and for allpurposes.

FIELD

The present technology relates generally to medical devices and methods,and more particularly, to delivery systems and methods for deliveringimplant devices to a target anatomy.

BACKGROUND INFORMATION

Vascular disease caused by stenosis or narrowing of a vessel is commonlytreated by endovascular implantation of scaffolding devices such asstents, often in combination with balloon angioplasty, to increase theinner diameter or cross-sectional area of the vessel lumen. Otherserious vascular defects include aneurysm in which a bulge or bubbleprotrudes out in a radial direction from the vessel that, if leftuntreated, may continue expanding until it bursts thereby causinghemorrhaging from the vessel. Endovascular implantation of scaffoldingdevices or stents can also be used to treat aneurysms to occlude,partially occlude, and/or assist in the implantation of a coil into theaneurysm.

Treating arteriosclerosis and aneurysms in vessels of the brain byendovascular implantation of stents and stent-like devices isparticularly challenging due, in part, to the tortuosity of thevasculature and the small size of the vessels. Further, the risk ofstroke and thromboembolic complications is high due to the release ofthrombotic material during delivery of the stent and, in the case offlow diverters for treatment of aneurysm, can block blood flow to branchvessels. Stent length also poses a risk for further thromboemboliccomplications.

SUMMARY

It would be advantageous, in particular, in cases where it might beimpossible to advance a catheter deep into the vasculature, to providean anchoring delivery system to provide support during delivery of animplant (or during any other procedures employing the advancement ofsheaths or catheters) to provide a faster, easier and more efficientendovascular implantation of stents and other implantable devices in thetreatment of cerebrovascular diseases. For example, an anchoringdelivery system may be beneficial during interventions within thecerebral vasculature involving the delivery of implants such as stents,flow diverters and coils, through tortuous or complex target anatomy.

In an aspect, described is a method of delivering an implant in anintracranial vessel. The method includes deploying an anchor of atethering device in an anchoring vessel forming a first fixation point.The tethering device has a tether extending proximally from the anchor.The method includes advancing a guide-sheath to a location near theanchoring vessel. The guide-sheath has at least one lumen. The methodincludes attaching the guide-sheath to the tether of the tetheringdevice forming a second fixation point proximal to the first fixationpoint, delivering an implant through the lumen of the guide-sheathtowards a treatment site distal to the first fixation point and locatedwithin an intracranial vessel, and deploying the implant at thetreatment site.

The implant can be a balloon-expandable stent, a self-expanding stent,or a flow diverter. The treatment site can be an aneurysm or a stenosisor other treatment site within a vessel. The first fixation point can beformed in the anchoring vessel near a bifurcation between the anchoringvessel and a vessel leading to the treatment site. Delivering theimplant through the lumen can tension the tether between the firstfixation point and the second fixation point. Deploying the anchor caninclude deploying the anchor from a low profile configuration to ahigher profile configuration. Advancing the guide-sheath can includeadvancing the guide-sheath over the tether such that the tether extendsat least in part through the at least one lumen of the guide-sheath. Theguide-sheath can include at least a second lumen, and the tether canextend through at least a portion of the second lumen. Attaching theguide-sheath to the tether can include using a tether gripper at thesecond point of fixation to attach the guide-sheath to the tether of thetethering device. The tether gripper can be on one or both of thetethering device and the guide-sheath. The method can further includepreventing prolapse of the guide-sheath during delivery of the implant.The method can further include resisting tension stored in theguide-sheath during delivery of the implant. The implant can be aself-expanding stent and deploying the implant at the treatment site caninclude unsheathing the self-expanding stent by withdrawing proximally aconstraint. The method can further include preventing the self-expandingstent from missing the treatment site during unsheathing. The method canfurther include removing the anchor from the anchoring vessel, andremoving the guide-sheath.

In an interrelated aspect, provided is a method of delivering an implantin an intracranial vessel including delivering a tethering device to ananchoring vessel. The tethering device includes a tether extendingproximally from an anchor. The method includes deploying the anchor ofthe tethering device in the anchoring vessel, advancing a guide-sheathover the tether of the tethering device to position an opening from theguide-sheath near an entrance of a target vessel bifurcating from theanchoring vessel, and delivering an implant through the guide-sheath toa treatment site distal to the anchoring vessel.

The method can further include attaching the guide-sheath to the tetherof the tethering device. The tethering device can fix and support theguide-sheath for delivering the implant through the guide-sheath. Theanchor can be deployed at an anchoring site in the anchoring vessel. Theguide-sheath can include a lumen to receive at least a portion of thetether. The guide-sheath can be attached to the tether at a point offixation proximal to the anchoring vessel. Delivering the implantthrough the guide-sheath can tension the tether between the anchordeployed in the anchoring vessel and the point of fixation. The implantcan be delivered through a first lumen of the guide-sheath and thetether can extend at least in part through the first lumen. The implantcan be delivered through a first lumen of the guide-sheath and thetether can extend at least in part through a second lumen separate fromthe first lumen. The implant can be a balloon-expandable stent, aself-expanding stent, or a flow diverter. The treatment site can be ananeurysm or a stenosis or other treatment site within a vessel. Themethod can further include preventing prolapse of the guide-sheathduring delivery of the implant. The method can further include resistingtension stored in the guide-sheath during delivery of the implant. Theimplant can be a self-expanding stent and deploying the implant at thetreatment site can include unsheathing the self-expanding stent bywithdrawing proximally a constraint. The method can further includepreventing the self-expanding stent from missing the treatment siteduring unsheathing. The method can further include removing the anchorfrom the anchoring vessel, and removing the guide-sheath.

In an interrelated aspect, provided is a method of delivering an implantin an intracranial vessel that includes advancing a guidewire near ananchoring vessel and exchanging the guidewire for a tethering device.The tethering device includes a tether extending proximally from ananchor. The method includes deploying the anchor of the tethering devicein the anchoring vessel, advancing a guide-sheath over the tether of thetethering device to position an opening from the guide-sheath near anentrance of a target vessel bifurcating from the anchoring vessel,attaching the guide-sheath to the tether of the tethering device, anddelivering an implant through the guide-sheath to a treatment site.

The anchor can be deployed at an anchoring site in the anchoring vesseldistal to the entrance of the target vessel. The guide-sheath caninclude a lumen to receive at least a portion of the tether. The lumencan be different or the same as the lumen through which the implant isdelivered. The guide-sheath can be attached to the tether at a point offixation proximal to the anchoring vessel. Delivering the implantthrough the guide-sheath can tension the tether anchor deployed in theanchoring vessel and the point of fixation. The implant can be aballoon-expandable stent, a self-expanding stent, or a flow diverter.The treatment site can be an aneurysm or a stenosis or another treatmentsite in the vessel. The method can further include preventing prolapseof the guide-sheath during delivery of the implant. The method canfurther include resisting tension stored in the guide-sheath duringdelivery of the implant. The implant can be a self-expanding stent anddeploying the implant at the treatment site can include unsheathing theself-expanding stent by withdrawing proximally a constraint. The methodcan further include preventing the self-expanding stent from missing thetreatment site during unsheathing. The method can further includeremoving the anchor from the anchoring vessel, and removing theguide-sheath.

In some variations, one or more of the following can optionally beincluded in any feasible combination in the above methods, apparatus,devices, and systems. More details of the devices, systems, and methodsare set forth in the accompanying drawings and the description below.Other features and advantages will be apparent from the description anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects will now be described in detail with referenceto the following drawings. Generally speaking the figures are not toscale in absolute terms or comparatively, but are intended to beillustrative. Also, relative placement of features and elements may bemodified for the purpose of illustrative clarity

FIGS. 1A-1C illustrate prolapse of a catheter within the aorta near thetakeoff of the great vessels;

FIGS. 1D-1F illustrate advancement of implant delivery systems through atypical sheath system;

FIG. 2A illustrates a perspective view of a tethering device, inaccordance with an implementation;

FIGS. 2B-2D illustrate detail views, taken from Detail A of FIG. 2A, ofan anchor coupled to a tether of a tethering device;

FIG. 3 illustrates a detail view of an anchor of a tethering device;

FIG. 4 illustrates a perspective view of a tethering device, inaccordance with an interrelated implementation;

FIG. 5A illustrates a detail view, taken from Detail A of FIG. 4, of adistal portion of a tethering device;

FIG. 5B illustrates a sectional view, taken about line A-A of FIG. 5A,of a distal portion of a tethering device;

FIG. 5C illustrates a detail view, taken from Detail A of FIG. 4, of adistal portion of a tethering device;

FIG. 5D illustrates a sectional view, taken about line A-A of FIG. 5C,of a distal portion of a tethering device;

FIG. 5E illustrates a detail view, taken from Detail A of FIG. 4, of adistal portion of a tethering device;

FIG. 5F illustrates a detail view, taken from Detail A of FIG. 4, of adistal portion of a tethering device;

FIG. 5G illustrates the tethering device of FIG. 5F after furtherexpansion of the anchor;

FIG. 5H illustrates a detail view, taken from Detail A of FIG. 4, of adistal portion of a tethering device, in accordance with an interrelatedimplementation;

FIG. 5I illustrates a detail view, taken from Detail A of FIG. 4, of adistal portion of a tethering device, in accordance with an interrelatedimplementation;

FIGS. 5J-5L illustrate detail views, taken from Detail A of FIG. 4, of adistal portion of a tethering device, in accordance with an interrelatedimplementation;

FIGS. 5M-5O illustrate schematic views of an anchoring vessel and ananchor;

FIGS. 5P-5R illustrate schematic views of a method of manufacturing ananchor of a tethering device, in accordance with an implementation;

FIGS. 5S-5U illustrate schematic views of further implementations of adistal portion of a tethering device, in accordance with an interrelatedimplementation;

FIGS. 6A-6B illustrate schematic views of a tethering device deployment,in accordance with an implementation;

FIGS. 7A-7B illustrate schematic views of a tethering device deployment,in accordance with an implementation;

FIG. 8A illustrates a schematic view of a tethering device in anunexpanded state, in accordance with an implementation;

FIG. 8B illustrates a schematic view of the tethering device of FIG. 8Ain an expanded state;

FIG. 8C illustrates a schematic view of the tethering device in anexpanded state of FIG. 8B and a locked state;

FIGS. 9A-9C illustrate schematic views of a tethering device deployment,in accordance with an implementation;

FIGS. 10A-10C illustrate schematic views of a tethering devicedeployment, in accordance with an implementation;

FIGS. 10D-10E illustrate schematic views of a further implementation ofa tethering device deployment, in accordance with an implementation;

FIG. 11 illustrates a perspective view of a tetherable guide-sheath, inaccordance with an implementation;

FIGS. 12A-12B illustrate detail views, taken from Detail B of FIG. 11,of a distal end of a tetherable guide-sheath;

FIGS. 12C-12D illustrate detail views, taken from Detail B of FIG. 11,of a distal end of a tetherable guide-sheath;

FIG. 12E illustrates a detail view of another implementation of a distalend of a tetherable guide-sheath;

FIG. 13 illustrates a sectional view of a distal end of a tetherableguide-sheath, in accordance with an implementation;

FIG. 14 illustrates a sectional view, taken about line A-A of FIG. 12B,of a distal end of a tetherable guide-sheath;

FIG. 15A illustrates a perspective view of a tetherable guide-sheath, inaccordance with an implementation;

FIG. 15B illustrates a detailed sectional view, taken from Detail B ofFIG. 15A, of a distal portion of a tetherable guide-sheath, inaccordance with an implementation;

FIG. 15C illustrates a detailed sectional view, taken from Detail B ofFIG. 15A, of a distal portion of a tetherable guide-sheath, inaccordance with an implementation;

FIGS. 16A-16B illustrate sectional views of a tetherable guide-sheath,in accordance with an implementation;

FIG. 17A illustrates a support guide during retrieval of an anchoringstructure;

FIG. 17B illustrates the retrieved anchoring structure in a tip of thesupport guide of FIG. 17A;

FIG. 18 illustrates a distal end of an anchoring delivery system havinga tethering device in a tether lumen of a tetherable guide-sheath and aworking device in a working lumen of the tetherable guide-sheath, inaccordance with an implementation;

FIG. 19 illustrates a distal end of an anchoring delivery system havinga tethering device in a tether lumen of a tetherable guide-sheath and aworking device in a working lumen of the tetherable guide-sheath, inaccordance with an implementation;

FIG. 20 illustrates a distal end of an anchoring delivery system havinga tethering device and a working device in a same lumen of a tetherableguide-sheath, in accordance with an implementation;

FIG. 21 illustrates a perspective view of a tetherable guide-sheath, inaccordance with an implementation;

FIG. 22 illustrates a sectional view, taken about line B-B of FIG. 21,of a tetherable guide-sheath, in accordance with an implementation;

FIG. 23 illustrates a sectional view, taken about line C-C of FIG. 21,of a tetherable guide-sheath, in accordance with an implementation;

FIG. 24 illustrates a sectional view of a proximal end of the tetherlumen of a tetherable guide-sheath, in accordance with animplementation;

FIG. 25 illustrates a tether gripper of a tetherable guide-sheath, inaccordance with an implementation;

FIG. 26 illustrates a tether gripper of a tetherable guide-sheath, inaccordance with an implementation;

FIG. 27 illustrates a tether gripper of a tethering device, inaccordance with an implementation;

FIG. 28 illustrates a method of using an anchoring delivery system todeliver a working device;

FIGS. 29A-29F illustrate operations of a method of using an anchoringdelivery system to deliver a working device;

FIG. 30 illustrates a method of using an anchoring delivery system todeliver a working device, in accordance with an implementation;

FIGS. 31A-31D illustrate operations of a method of using an anchoringdelivery system to deliver a working device, in accordance with animplementation;

FIG. 32 illustrates a method of using several anchoring delivery systemsto gain access to a target vessel, in accordance with an implementation;

FIGS. 33A-33B illustrate operations of a method of using severalanchoring delivery systems to gain access to a target vessel, inaccordance with an implementation;

FIG. 34 illustrates a method of using several anchoring delivery systemsto gain access to a target vessel, in accordance with an implementation;

FIGS. 35A-35C illustrate operations of a method of using severalanchoring delivery systems to gain access to a target vessel, inaccordance with an implementation;

FIG. 36 illustrates a flowchart of a method of deploying an anchoringdelivery system, in accordance with an implementation;

FIG. 37A-37B illustrate schematic views of an anchoring delivery systemdeployed in a target anatomy, in accordance with an implementation;

FIG. 38 illustrates a schematic view of an anchoring delivery systemdeployed in a target anatomy, in accordance with an implementation;

FIG. 39 illustrates a flowchart of a method of deploying an anchoringdelivery system, in accordance with an implementation;

FIG. 40A-40D illustrate schematic views of an anchoring delivery systemdeployed in a target anatomy, in accordance with an implementation;

FIGS. 41A-41D illustrate schematic views of an anchoring delivery systemdeployed in a target anatomy for advancing an implant delivery system,in accordance with an implementation;

FIGS. 42A-42D illustrate schematic views of an anchoring delivery systemdeployed in a target anatomy for advancing an implant delivery system,in accordance with an implementation;

FIGS. 43A-43E illustrate schematic views of buckling and tension storagewithin a typical procedural guide sheath; and

FIGS. 44A-44D illustrate schematic views of relieving tension storedduring advancement of an implant delivery system through an anchoringdelivery system, in accordance with an implementation.

It should be appreciated that the drawings are for example only and arenot meant to be to scale. It is to be understood that devices describedherein may include features not necessarily depicted in each figure.

DETAILED DESCRIPTION

Endovascular access of the neurovasculature requires navigation ofvessels, often tortuous and diseased, which can complicate delivery ofdevices such as intracerebral stents and their delivery systems.Resistance points during advancement of various implantable devicesthrough the vessel can lead to a chain reaction of events involving thebuckling and storage of tension within the catheter length. Further,many cases involve a trial and error iterative process of differentconstructs of supporting catheters and stiff wires to build a “tower”into the intracerebral vasculature—each iteration involving furtherguidance and support. This can be traumatic to the vessel through whichthe devices are passed and ultimately, the entire system can lose columnstrength and such that the devices fail to traverse to the desiredlocation.

To access the cerebral anatomy, guide catheters and guide sheaths areused to direct interventional devices, such as stents, coils, and flowdiverters, to a target site, such as an embolism, stenosis, or anintracranial aneurysm, from the access site. It can be challenging toestablish guide or sheath position in a fashion that is stable andprovides support for the device delivery. To maneuver the catheters intoposition, coaxial, triaxial, or quadraxial systems are often used inwhich a guidewire/microcatheter system is first deployed and coaxiallarger catheters are subsequently delivered. The clinical challenge,especially in the octogenarian population, is the elongation of theaortic arch against the fixed thoracic descending aorta, leading to ashifting of all great vessels, especially the brachiocephalic takeoff.Such shifting makes it more challenging to access the anatomy duringtreatment of, e.g., stroke, aneurysm, and other distally locatedvascular diseases. As catheters, wires, balloons, stents, or retrievablestructures are advanced through the great vessels, they have a tendencyto prolapse into the ascending aorta when pushed into a highly angulatedand/or tortuous anatomy.

Described herein are methods that include delivering an implant and/oran implant delivery system to a target vessel of a neurovascularanatomy. The methods can include delivering the implant through aworking lumen of a guide-sheath. More particularly, the guide-sheath canbe fixed to a tether of a tethering device, and the tether can beattached to an anchor expanded within an anchoring vessel. Thus, theanchored tethering device and tetherable guide-sheath system, i.e., theanchoring delivery system, may support the implant delivery systemduring delivery to the target vessel. The methods described hereinleverage the support provided by the anchoring delivery system, eitherfrom a transfemoral or transcervical route, to deliver implants withinthe cerebral vasculature with a very precise and accurate delivery with“one-to-one” tactile feedback and control. Precision and accuracy indelivery allows for the use of shorter devices that are better matchedto the target site, e.g. a stent that is as long as the stenosis or aflow diverter that covers only the neck of an aneurysm. This also canreduce the risk of poor apposition of these stent products to the vesselwall, easing the concern for stent thrombosis. The stent delivery systemcan include a balloon expandable implant, e.g., a non-shape memory stentor flow diverter as well as self-expanding implants.

The Challenge of Intracerebral Implant Placement

Referring now to the figures, when advancing a catheter 900, such as acatheter of an implant delivery system, in tortuous anatomy or againstresistance at a tip of the catheter 900, such as shown in FIGS. 1A-1B,resistance to movement may be felt by an operator. For example, as tippoint A encounters a vessel wall, e.g., within a tortuous anatomy, acounter force is directed through the catheter 900 at point B.Particular to the involvement of access to the great vessels, e.g., thebrachiocephalic, common carotid, or subclavian takeoffs from an aorta atthe aortic arch AA, there is a dramatic transition from the “free space”of the aorta arch AA to the great vessels, and to the target vessel(e.g. a 2-3 mm intracerebral artery). Referring to FIG. 1C, the catheter900 body in the aorta arch AA is “free” and buckles into the arch AA,which offers no resistance and can be a potential space for “storage” ofcatheter length and tension. The buckling at the level of theaorta/great vessel takeoff into the free space of the aorta can lead towithdrawal of the catheter 900 tip at tip point A, as well as aguidewire (910) that the catheter 900 is being delivered over. Theanchoring delivery systems described herein provide guide support by“fastening” and supporting the body of the catheter 900 at a point toovercome the resistance at tip point A to advance the catheter 900toward a target site 925 in the target vessel 1906.

FIGS. 1D-1F show traditional sheath and support systems that can provide“support from below.” FIG. 1D shows a sheath 905 used inneuro-intervention that either inserts through a short sheath at thegroin or are themselves advanced to the level of the CCA or ICA. A guidecatheter 900 is often advanced through the sheath 905 to gain a higherlevel of support to the petrous or bony ICA. Referring to FIG. 1E, aprocedural guidewire 910 and a stent delivery system 915 for delivery ofan implant may then be advanced through the sheath 905 or through acoaxial system including the sheath 905 and the guide catheter 900.

It should be appreciated that phrases like “working device,” “stentdelivery system,” or “implant delivery system” may be usedinterchangeably herein and are not intended to be limiting. For example,when referring to “stent delivery system”, the implant payload may be a“stent” in the traditional sense, but may also be a flow diverter havinga scaffold configured to divert blood flow around an aneurysm sac, or anembolic coil configured to fill the aneurysm sac, or a combinationthereof. Further, the implant may be a self-expanding implant or stentthat is contained within a delivery system sheath, or an implant on aballoon that is actively expanded. Thus, as used herein “implantdelivery system” or “stent delivery system” incorporates bothself-expanding (SE) systems and balloon-expandable (BE) systems and isnot intended to be limiting. An SE stent system is illustrated in thefigure, and thus, the catheter 900 can represent the outer sheath of theSE stent system surrounding the stent in the undeployed/unexpandedstate. In the example, there is an aneurysm shown as the target site 925in the target vessel 1906 for implant placement. It should beappreciated that the target site 925 for implant placement can vary andneed not include an aneurysm. For example, the target site 925 can be anoccluded, partially occluded, or otherwise narrowed or stenotic regionof a vessel.

Referring to FIG. 1F, the stent delivery system 915 can meet anobstruction or, as in the case shown, an extreme tortuosity 930 such asthe carotid siphon or other tortuous locations common in theintracerebral anatomy. These resistance points are often met with stentadvancement and can lead to a chain reaction of events in typical cases.This can also occur with inflation balloon systems, simple microcatheteradvancement or even guidewire advancement depending on how “tenuous” thepurchase of the sheath and guide systems is. As mentioned above, manycases involve a trial and error iterative process of differentconstructs of supporting catheters and stiff wires to build the “tower”to the intracerebral vasculature that can be traumatic to thevasculature and to the patient and prolong procedure times.

Still with respect to FIG. 1F, the standard sheath system placed in theICA is shown with advancement of a stent delivery system 915 targetingthe distal target site 925. Advancement of the stent delivery system 915with forward push at the rotating hemostatic valve (RHV) 434 at point Aof FIG. 1F can lead to advancement of the stent delivery system 915through the sheath 905, out of the sheath tip 906 and into the tortuousdistal carotid and cerebral anatomy. The tip of the stent deliverysystem 915 can be guided by the course of a previously positionedprocedural guidewire 910 and may encounter an area of tortuosity 930where it meets resistance in taking that curve (near point B of FIG.1F). Further advancement of the stent delivery system 915 can lead todownward force that can buckle the stent delivery system 915 and thesheath 905 (point C in FIG. 1F).

The sum effect of forward pressure in such systems can be stentadvancement to a point of ultimate resistance and stoppage. At thispoint, continued advancement can create a downward and lateral force onthe catheter systems below (point B in FIG. 1F). The chain reaction thatcan follow uncovers a series of buckling and prolapse points along thesystem course, for example, from the femoral anatomy to the stent tip asshown in dotted lines. A common buckle point is at the transition fromthe aorta AA to the target great vessel (point C in this case, theascending aorta and the brachiocephalic artery). Because of the bendingand the downward force, this buckle point often pulls the entireguidewire/stent delivery system/sheath system downwards with continuedforward stent delivery system 915 advancement. The casual observer cansee a resulting appearance of the stent delivery system 915 moving“backwards” on fluoroscopic imaging with advancement, all theadvancement of force leading to catheter prolapse into the aorta AA anderosion of the support to advance wires or stent systems northward. Thecourse of the coaxial stent delivery system 915 and sheath 905 may leadto further buckling and prolapse throughout the aorta AA, which canforce the course of the coaxial system to “take the greatest curve” upto the stent tip. Prolapse and loss of length can cause more and morewithdrawal of the stent delivery system 915 tip, frustrating theoperator and leading to prolonged procedure times and complications fromthe back and forth movement required to advance systems in this“slippery slope” situation. The entire system may lose column strengthas the downward and lateral pressures create awkward turns and“corkscrew” paths through which guidewire and stent fail to traverse.This can lead to complete displacement of the system and loss ofpurchase in the great vessel.

The Anchoring Delivery System

The anchoring delivery systems described herein can rapidly,consistently and easily create a transfemoral guide-catheter positionwith “100% support” by creating a tension between an insertion site,such as a femoral insertion site, and an anchoring vessel, such as theright or left subclavian (RSA or LSA) or external carotid artery (ECA).Additionally, and as will be described in more detail below, a secondaryanchoring may use the junction of a tether of a tethering device and atetherable guide-sheath as a capture point for the carina of abifurcation between ECA and CCA (for LSA/RSA, between the bifurcation ofthe innominate or brachiocephalic artery and subclavian). It should beappreciated that although much of the description refers to theimplantation of a sheath using a transfemoral route of insertion, otherroutes are considered herein. For example, a transcervical route inwhich a sheath enters the vascular space at the level of the commoncarotid artery (CCA) or internal carotid artery (ICA) is also consideredherein. Where the method involves using an anchoring delivery systemthat includes a tethering device and a tetherable guide-sheath insertedtransfemorally, methods are also considered herein where a sewn-insheath entering the vascular space from a transcervical route that couldbe fastened or sutured in place to mitigate any backing-out orpulling-in of the sheath tip relative to the push-and-pull of typicalcatheter interventions as described in more detail herein.

The following discussion of the anchoring delivery system incorporatesthe right ECA as the anchoring vessel, as this is will commonly be usedin more challenging anatomy. The anchoring vessel, however, may be anyvessel or anatomy that an anchor of the tethering device may be securedwithin. Typically, an operator will go straight for the ipsilateral ECAor ICA above (the bifurcation of the CCA) as this is the target of stiffwire placement for delivery of standard sheaths. An anchoring arterywill preferentially not be in the path to the cerebral target, thus,anchoring target arteries will be the external carotid artery (ECA) orsubclavian artery (SA) to access the internal carotid artery (ICA) orcommon carotid artery (CCA), respectively. The choice of ipsilateral SAor ECA as the anchoring target can depend on anatomy and clinicalindication. For instance—it may be more challenging for certainanatomies to easily reach the ECA; as well, if carotid stenting is beingcontemplated—anchoring in the SA will give the operator guide support toaccess most any ICA through the generally non-tortuous thoracic CCA.

Described herein are anchoring delivery systems for providing fixationand support for the advancement of one or more working devices. Theanchoring delivery systems described herein can include one or moretethering devices and a guide-sheath tethered by the one or moretethering devices and configured to receive and support the advancementof an implant delivery system therethrough. Each of the components ofthe anchoring delivery system and methods of using the anchoringdelivery system for implant delivery will be described in more detailbelow.

It should be appreciated that the configuration of the tethering devicesdescribed herein can vary. The tethering device can be used with variousguide-sheaths as described herein, including the tetherable guide-sheathdescribed in more detail below as well as any of a variety of comparablecommercially available guide-sheaths to form an anchoring deliverysystem 10. For example, the tethering devices described herein can beused with guiding sheaths having an ID between 0.087″-0.089″ such as theCook SHUTTLE 6F (Cook Medical, Inc., Bloomington, Ind.), TerumoDESTINATION 6F (Terumo Europe NV), Cordis VISTA BRITE TIP (Cordis Corp.,Hialeah, Fla.), and Penumbra NEURON MAX 088 (Penumbra, Inc., Alameda,Calif.), or comparable commercially available guiding sheath. Further,it should be appreciated that the working devices for advancing throughthe guiding sheath can vary and need not be limited to theimplementations shown in the figures. The guiding sheath, whether thetetherable guide sheath 400 or another commercially-available guidingsheath, can be used to deliver any of a variety of working devicesconfigured to provide treatments such as large-bore catheters,aspiration thrombectomy, advanced catheters, wires, balloons,retrievable structures such as coil-tipped retrievable stents“Stentriever,” stents, flow diverters, and a variety of otherimplantable devices.

Tethering Devices

The anchoring delivery system 10 can include a tethering device 100.FIG. 2A shows a perspective view of a tethering device 100 in accordancewith an implementation. The tethering device 100 can include a distalanchor 102 coupled to a proximal tether 104, for example, by a distaland/or a proximal joint 108. The tether 104 can be an elongate elementextending proximally from the distal anchor 102 such as a filamentouselement having an outer diameter that is small and flexible enough tocurve through the tortuous vessels of the cerebral vasculature withoutkinking. Keeping the tether 104 to a small diameter allows the diameterof a tethered guide-sheath sized to receive the tether 104 to be assmall as possible minimizing the access arteriotomy size. In at leastsome implementations, the tether 104 has a relatively low “pushability”such that it is generally not useful for advancing the anchor 102through the vasculature without the assistance of a delivery tool.However, upon application of a proximal pulling force on the tether 104,for example when the tethering device 100 is anchored in a vessel by theanchor 102, the tether 104 is strong enough to maintain the tetheringdevice 100 in a tensioned or taut state, as will be described in moredetail below. The anchor 102 can have any of a variety of configurationsas will be described in more detail below. Generally, the anchor 102 hasa first, low-profile (unexpanded or constrained) configuration such thatthe anchor 102 may be delivered to the anchoring anatomy. The anchor 102also has a second, higher-profile (expanded or unconstrained)configuration after delivery to and deployment within the targetlocation such that the anchor 102 anchors (itself and the tetheringdevice 100) within the target anatomy. It should be appreciated that useof the terms “expanded” and “unexpanded” as used herein with regard tothe anchor 102 of the tethering device 100 refer generally to an overallshape or profile of the anchor 102 that is, in the case of an “expanded”anchor, greater than the overall shape or profile of the anchor 102during delivery to the target anatomy or, in the case of an “unexpanded”anchor, less than the overall shape or profile of the anchor 102 duringanchoring in the target anatomy, respectively. “Expanded” and“unexpanded” as used herein are not intended to require any particulartype of change in profile of the anchor 102.

The anchor 102 can be deployable from the unexpanded state to theexpanded state to fix a distal end of the tether 104 at an anchoringsite in an anchoring vessel of a target anatomy, as described below.Thus, the anchor 102 may have enough radial strength in the expandedconfiguration to grip the anchoring anatomy and resist a proximal pullon the tether 104. The anchor 102 is generally configured to anchorwithin the anchoring vessel, as opposed to dilating a stenosis orscaffold the vessel such as with stents. However, it should beappreciated that the anchors 102 described herein can anchor in a mannerthat also dilates, scaffolds, embeds, and/or distorts the anchoringvessel within which the anchor 102 is anchored. The anchors 102described herein can also facilitate anchoring of the tethering device100 by other features that do not necessarily involve a change in shape,such as by externalizing a portion of the wire and/or incorporatingsuperficial magnetic features in order to clamp outside the body, aswill be described in more detail below.

Still with respect to FIG. 2A, the tether 104 of the tethering device100 can be an elongated member extending from a proximal end 106 of thetethering device 100 to a distal joint 108 and having an outer surfaceextending along a longitudinal axis. The tether 104 can be stifferand/or less prone to bending than the wires typically attached toretrievable structures, such as a Merci retriever or a Stentrieverdevice, such that upon anchoring of the distal anchor 102 into a vesselthe tether 104 can serve a supportive function to support a guide-sheathagainst buckling or prolapse, which will be described in more detailbelow. The tether 104 can also be formed by a combination of elementsproviding the proper supportive function. The tether 104 can havevarious dimensions and/or material configurations. The dimensions and/ormaterial configurations of the tether 104 can be selected to achieve adesired tensile strength, flexibility, and trackability. In someimplementations, a diameter of the tether 104 ranges from 0.005 inchesto 0.025 inches, e.g., 0.008 inches, or 0.009 inches, or 0.010 inches,or 0.035 inches, depending on the degree of support that the tether 104provides. The tether 104 can be a solid wire rod, a ribbon, or ahypotube of stainless steel or NiTi. In some implementations, the tether104 can be a stainless steel rod, ribbon or hypotube. In otherimplementations, the tether 104 can be Drawn Filled Tubing (DFT) with aradiopaque core, such as an outer sheath of a composite to providestrength and a core material to provide superelasticity, conductivity,radiopacity, resiliency, etc. In some implementations, the tether 104can be DFT of Nickel titanium with a radiopaque core such as platinum ortantalum.

The tether 104 can have several different cross-sectional areas atlocations along its longitudinal axis between the proximal end 106 ofthe tether 104 to where it couples with the anchor 102. For example, aproximal section near the proximal end 106 of the tether 104 can have afirst cross-sectional diameter. The first cross-sectional diameter maybe sized, for example, to favor support over trackability. Similarly,the tether 104 can include a distal section distal to the proximalsection that has a different cross-sectional diameter compared to thefirst cross-sectional diameter. For example, the distal section caninclude a second cross-sectional diameter that is smaller than the firstcross-sectional diameter of the proximal section. As such, the distalsection of the tether 104 can be configured to favor trackability oversupport.

The anchor 102 of the tethering device 100 can be sized to engage arange of vessel diameters, i.e., covering the lumen diameters to providesolid apposition against target anchor 102 sites such as the proximalCCA, proximal and mid-subclavian, and the external carotid artery (ECA).For example, the anchor 102 of the tethering device 100 can engagearteries of about 1 mm inside diameter to arteries with 40 mm insidediameters. For some procedures, it may be more common to anchor inarteries ranging from 2 mm inside diameter to 10 mm inside diameter. Inother implementations, the anchor 102 of the tethering device 100 may besized to be able to engage smaller arteries such as side branches. Incomparison to conventional retrievable structures used in SMATprocedures, which are typically rather flimsy and unable to anchoragainst an artery wall, the anchors described herein are specificallydesigned to anchor within a target anatomy. For example, the anchorsdescribed herein can be sized to anchor within internal carotid artery(ICA), middle cerebral arteries at the M1 segment, Vertebral, Basilarvessels, or vessels generally larger than 3 mm. The anchors describedherein can also be sized to anchor within vessels in the insular segmentarteries at the M2 segment, P1 or vessels which are generally within the2 mm-3 mm range. The anchors described herein can also be sized toanchor within vessels that are at the M3 segments or within vessels thatare generally less than 2 mm.

The anchor 102 of the tethering device 100 can have any of a variety ofconfigurations as described herein. For example, the anchor 102 caninclude an expandable structure configured to self-expand upon releaseof a constraint and/or expand when a force is applied. In someimplementations (e.g., FIGS. 2B and 2D), the anchor 102 of the tetheringdevice 100 can include a self-expanding material, such as nitinol, toexpand to an understood diameter in the air and exert a controllable andconsistent radial outward pressure when expanded and constrained withina vessel. In an implementation, the anchor 102 can include a closed-cellstent like structure, e.g., made of self-expanding material like nitinolthat may be set to a desired shape, for example, by a heat set process.In other implementations, the anchor 102 of the tethering device 100 caninclude a non-self-expanding material (e.g., FIG. 2C) such that theanchor 102 expands when a force is applied.

The anchor 102 can be collapsed to a first configuration for deliveryinto the target vessel, expanded to a second configuration upondeployment in the target vessel and subsequently collapsed to or towardsthe first configuration for removal from the vessel. The anchor 102 ofthe tethering device 100 can collapse or be constrained to a smalldimension such that it can be delivered through the lumen of a deliverycatheter, e.g., a microcatheter or finder catheter as described below.In some implementations, the anchor 102 of the tethering device 100 canbe actively collapsed using one or more additional features orcomponents. The anchor 102 can additionally or optionally be malleablesuch that it can be pulled into the small dimension. The anchor 102 ofthe tethering device 100 can be deployed by unsleeving the anchor 102,e.g., advancing the anchor 102 from the lumen of the delivery catheter,retracting the delivery catheter to expose the anchor 102 from thelumen, or a combination or the two.

FIG. 2B is a detail view taken from Detail A of FIG. 2A of an anchor 102coupled to a tether 104 of a tethering device 100. As described above,the tether 104 can terminate at a distal joint 108 between the proximalend 106 and the anchor 102. The anchor 102 can be physically connectedor attached to the tether 104 by one or more joints. The joint 108 maybe a permanent attachment between the tether 104 and the anchor 102,such as a welding joint or other attachment joint. Alternatively, theanchor 102 can be detachably connected to the tether 104 at the joint108. For example, the tether 104 can terminate at the distal joint 108,and the distal joint 108 may be severable at the discretion of anoperator to decouple the anchor 102 from the tether 104. The decouplingbetween the anchor 102 and the tether 104 can be a permanent orreversible decoupling. For example, the distal joint 108 between thetether 104 and the anchor 102 may be an adhesive joint having apredetermined breaking stress, such that when sufficient pulling forceis applied to the tether 104, the distal joint 108 breaks to detach thetether 104 from the anchor 102. In another implementation, the distaljoint 108 can be a threaded joint. For example, the tether 104 caninclude an external thread at the distal joint 108 that engages with aninternal thread of a tube section located at a proximal end or a distaljoint 108 of the anchor 102. Thus, the operator can rotate the tether104 around the longitudinal axis of the tethering device 100 when theanchor 102 is anchored in the anchoring anatomy to unscrew the tether104 from the anchor 102. It should be appreciated that other mechanismsof detachment between the tether 104 and the anchor 102 are consideredherein. Detachment of the anchor 102 from the tether 104 can be usefulwhere re-sheathing of the anchor 102 by a delivery catheter or atetherable guide-sheath, which will be described in more detail below,is not possible or may cause rupture or damage to a vessel. Thus, theanchor 102 can be left behind in the vessel and the tether 104 may besafely removed from a patient.

As shown in FIG. 2B, the anchor 102 can include several convolutedstruts 202 extending from the distal joint 108 to respective distalstrut ends 204. The convoluted struts 202 can follow any path from thedistal joint 108 to the distal strut ends 204. In an implementation, theconvoluted struts 202 can extend in a generally longitudinal directionwhen the anchor 102 is in the unexpanded or constrained state, and theconvoluted struts 202 can expand to extend in a generally spiraldirection when the anchor 102 is in the expanded state. Thus, atransverse dimension of the convoluted struts 202 can be less in theunexpanded state than in the expanded state, and a longitudinal lengthof the convoluted struts 202 can be greater in the unexpanded,constrained state than in the expanded state. As shown in FIG. 2B, whenthe convoluted struts 202 expand together they can form a weavedstructure that can engage an inner surface of the anchoring vessel. Therespective proximal ends of the convoluted struts 202 can be attached tothe distal joint 108 and the distal strut ends 204 can be freelysuspended. More particularly, the distal strut ends 204 may not beattached to each other such that the struts 202 are individuallycantilevered from the distal joint 108. However, the distal strut ends204 can be coupled to each other, e.g., by being commonly connected to asecond joint of the anchor 102, for example as shown in FIG. 5A, whichwill be described in more detail below. The struts 202 can alsoincorporate one or more barbs or cleats to improve their anchoringstrength within the vessel and prevent slippage of the anchor 102 in aproximal direction, for example, upon a pulling force being appliedduring use.

FIG. 2C is a detail view taken from Detail A of FIG. 2A of an additionalimplementation of an anchor 102 coupled to a tether 104 of a tetheringdevice 100. The anchor 102 can include a balloon 206 having an outersurface containing an internal volume. The tether 104 can include atubular structure, such as a hypotube, extending from the proximal end106 to a distal joint 108. An inner lumen of the tether 104 can be influid communication with the internal volume of the balloon 206 throughan inflation port 208 formed in a sidewall of the tether 104 hypotube.To facilitate tracking of the anchor 102, the distal joint 108 of thetether 104 can be connected to a soft, distal tip 210. The distal tip210 can be a spiral wire coil or other configuration tip that isflexible and atraumatic to the anchoring anatomy.

FIG. 2D is a detail view taken from Detail A of FIG. 2A of an additionalimplementation of an anchor 102 coupled to a tether 104 of a tetheringdevice 100. The anchor 102 can include a self-expandable structurecapable of self-expanding from a first, collapsed state to a second,expanded state. The tether 104 can connect to the anchor 102 at a distaljoint 108 and an outer diameter of the anchor 102 can enlarge from thedistal joint 108 towards the distal-most terminus of the anchor 102.Thus, when the self-expandable structure is expanded, an outer dimensionof the structure from the distal joint 108 towards a distal-mostterminus of the anchor can gradually widen to a maximum dimension. Theself-expandable structure of the anchor 102 can include a sequence ofanchor rings 211 disposed longitudinally relative to each other. Theanchor rings 211 can be connected by one or more ring connectors 212,such that the anchor rings 211 transmit longitudinal force between eachother. The self-expandable structure can have an open cell or a closedcell configuration, as is known in the art, depending on the number ofring connectors 212 used between adjacent anchor rings 211.

As mentioned above, the anchor 102 may have enough radial strength inthe expanded configuration to grip the anchoring anatomy and resist aproximal pull on the tether 104. FIG. 3 is a detail view of animplementation of an anchor 102 of a tethering device 100 that includesone or more ribs or struts 302 making up the expandable anchor 102. Theconfiguration of the struts 302, for example, their orientation and/orhow they provide a shape to the anchor 102 as a whole, as well as byincorporating features such as barbs, hooks, cleats, surface textures,etc. can be designed such that they aid to resist longitudinal movementof the anchor 102 once engaged with the anchoring anatomy. For example,the struts 302 can be configured to resist being pulled proximally whenthe strut 302 is engaged with tissue. In some implementations, the strut302 can be specifically designed to resist proximal movement within theanchoring anatomy, but may still be pushed in a distal direction throughthe anchoring anatomy. Thus, the anchor 102 can provide directionallybiased resistance to movement within the anchoring anatomy. As shown inFIG. 3, the struts 302 can include respective strut surfaces 304, whichmay face generally outward relative to a longitudinal axis 306 passingthrough the tether 104. The struts 302 can be oriented, e.g., by designor shape setting, such that a strut plane 308 passing through the strut302 parallel to the strut surface 304 is directed at an angle α to thelongitudinal axis 306. This may be referred to as “fish scaling”. Moreparticularly, the struts 302 or the cells of the anchor 102 can bendoutward during deployment such that a longitudinal plane passing throughthe struts 302 becomes angled relative to the longitudinal direction.For example, the angle can be proximally directed such that the strut302 will tend to dig into a tissue at the anchoring anatomy when theanchor 102 is pulled proximally. Thus, the “fish-scaled” struts 302 canresist a proximal pull applied to the tether 104. By contrast, the angleof the strut plane 308 can allow the struts 302 to be pushed distallywithout the struts 302 digging into the tissue. Thus, the anchor 102 canbe configured to grip the anchoring anatomy in one direction (e.g.proximally) but not in another direction (e.g. distally). “Fish-scaling”in stent design is often deemed to be undesirable for certainindications. However, “fish-scaling” of the anchor 102 in this contextcan be beneficial.

In addition to shaping the anchor 102 as a whole in a manner thatfacilitates gripping of the anchoring anatomy by the struts 302 can beindividually modified to facilitate such gripping. For example, thestrut surface 304 can be ribbed or roughened, e.g., by bead blasting orchemical etching, to increase friction between the tissue at theanchoring anatomy and the anchor 102. In an implementation, rather thanroughening the strut surface 304 by a secondary manufacturing process,the strut surface 304 can be manufactured by a process that does notinclude a polishing process that is otherwise applied to the remainderof the anchor 102. For example, the anchor 102 may be electropolishedduring manufacturing, but strut surface 304 may be masked during theelectropolishing process to avoid smoothing the strut surface 304. Inanother implementation, surface treatments such as applying an adhesiveto the outer surface of the struts 302 (or any other structural featureof the anchor 102) can be used to permanently or temporarily bond theanchor 102 with the tissue at the anchoring anatomy. The adhesive can beactivated upon contact with the tissue such that it does not cause theanchor 102 to stick to an inner surface of the tetherable guide-sheathor another catheter, e.g., a finder catheter, that the tethering device100 is delivered through.

As mentioned above, the anchor 102 of the tethering device 100 can alsobe designed to enhance anchoring by providing traction due toincorporation of one or more features that protrude from the anchor 102to anchor to the surrounding anatomy. For example, the anchor 102 caninclude features having a predetermined shape and size, such as one ormore barbs or hooks, that protrude from the sides of the anchor 102 toimbed into surrounding vascular tissue and grip the vessel when aproximal pull force is exerted on the tether 104. These grippingfeatures of the anchor 102, however, can be configured to collapse suchthat the anchor 102 can be removed from the vessel. In someimplementations, the features can be configured to yield and/orcollapsed when a distal tip of guide-sheath is advanced over them, aswill be described in more detail below. For example, the struts 202shown in FIG. 2B can incorporate one or more cleats or barbs on theirdistal ends to improve their grip within the anatomy. The cleats canprotrude outward toward the vessel wall such that upon expansion orrelease of the struts 202 from their constrained configuration thepointed ends of the cleats engage with the vessel wall. The cleats canbe configured to undergo flexure upon re-sheathing such that they can beremoved from the anatomy. For example, the cleats in the unconstrainedconfiguration can bend outward such that their pointed ends extendtowards the vessel wall and/or bend back towards the proximal directionto improve engagement with the vessel wall, for example, upon proximalpull force on the tethering device. Their pointed ends can be urged awayfrom the vessel wall during re-sheathing, for example, such that theyflex back in the distal direction upon distal advancement of a sheath ortubular structure to once again constrain the struts 202 in a lowprofile configuration.

It should be appreciated that reference to one implementation of ananchor as having a particular feature, such as a surface treatment,anchoring feature, cleat, barb, etc., may be incorporated into any ofthe various anchors described herein.

FIG. 4 shows a perspective view of another tethering device inaccordance with an implementation having an anchor 102 physicallyconnected to a tether 104 and further including a pusher tube 109. Thetether 104 can be attached to the anchor 102 at one or more joints 108,such as a first joint 108 distal to the anchor 102 and/or a second joint108 proximal to the anchor 102. The pusher tube 109 can slide distallyand proximally relative to the tether 104, and may be removed prior todelivery of a guide-sheath over the tether 104. The tether 104 and/orpusher tube 109 can be gripped and advanced to push the anchor 102forward for delivery to an anchoring site in a target anatomy.Similarly, the pusher tube 109 can be retracted over the tether 104 toremove the pusher tube 109 from the target anatomy, while keeping theanchor 102 and the tether 104 in place to receive a tetherableguide-sheath, as will be described in more detail below. In someimplementations, the anchor 102 is collapsed or constrained inside thepusher tube 109 and the pusher tube 109 is used to provide some heft andpushability such that the pusher tube 109 is used to advance anotherwise flexible wire of the tether 104, for example through amicrocatheter, finder catheter, or diagnostic catheter. The size of thepusher tube 109 can remain small enough such that a guide-sheath can bethread onto it, as will be discussed in more detail below.

Referring to FIG. 5A, a detail view, taken from Detail A of FIG. 4, of adistal portion of a tethering device is illustrated in accordance withan implementation. The anchor 102 can be configured to expand when aforce is applied. The anchor 102 can include a closed-cell stent likestructure, e.g., made of self-expanding material like nitinol. Theanchor 102 can include a slit tube structure, for example, a structurethat includes a tube made of a self-expanding material like nitinol, andhaving several longitudinal slits or slots that allow the tube to beexpanded from an unexpanded, tubular shape, to an expanded shape.Accordingly, the anchor 102 may be set to a desired shape, for example,by a heat set process. Alternatively, the anchor 102 can be formed fromspring steel, alloys, or even polymeric material. Furthermore, thetether 104 can include an anchor wire 111 extending through a runnertube 113. The anchor wire 111 can be seen in FIG. 5A although is hiddenbehind a middle rib 115 of the slit tube in FIG. 5D. The anchor wire 111can connect to the anchor 102 at the distal joint 108. Similarly, therunner tube 113 may be connected to the anchor 102 at the proximal joint108. Thus, a withdrawal or pulling load applied to the anchor wire 111can lead to compression of the anchor 102 between the distal joint 108and the proximal joint 108. The compression may cause outward bowing andexpansion of the ribs 115 of the anchor 102. Accordingly, when actuatedwithin an anchoring vessel, the anchor 102 may secure the tetheringdevice 100 within the target anatomy.

FIG. 5B is a sectional view of FIG. 5A taken about line A-A, of a distalportion of the tethering device 100 shown in FIG. 4. The anchor 102 canbe a self-expanding structure having one or more rib segments 115interconnected with one or more spreader segments 117. The anchor 102can also include a slit tube structure having one or more rib segments115 extending longitudinally between a proximal joint 108 and a distaljoint 108 as shown in FIGS. 5D-5G. Each rib segment 115 can have adistal end attached to the distal joint 108 and a proximal end attachedto a distal end of a corresponding spreader segment 117. Similarly, eachspreader segment 117 can have a proximal end connected to the proximaljoint 108 of the anchor 102. In an implementation, the proximal joint108 includes a tether collar 119, such as a band that is swaged, glued,or otherwise affixed to one or more of the anchor 102 or the runner tube113 of the tether 104.

Still with respect to FIGS. 5A-5B, the anchor wire 111 can include arigid member designed to transmit longitudinal force to the distal joint108. Thus, the anchor wire 111 can be fixed to the distal joint 108, andcan impart an expansion force to the anchor 102 when pulled. Moreparticularly, when a compressive load is applied to the anchor 102between the distal joint 108 and the tether collar 119, the rib segments115 may tend to bow outward, and the spreader segments 117 may maintaina lateral separation between the proximal ends of the rib segments 115and the anchor wire 111. Accordingly, the anchor 102 may expand from anunexpanded state, e.g. a tubular shape, to an expanded state, e.g. abulbous shape. The anchor wire 111 may have an outer diameter of 0.006inch, the runner tube 113 may have an outer diameter of 0.011 inch, andthe pusher tube 109 may have an outer diameter of 0.020 inch. The wallthicknesses of the runner tube 113 and the pusher tube 109 may beminimized for their respective materials, which may be a medicallyacceptable material such as nitinol or stainless steel.

FIG. 5C is a detail view of a distal portion of a tethering device. Aswith other implementations, the anchor 102 can be configured toself-expand and/or expand when a force is applied to it. The anchor 102can include a slit tube structure, for example a tube made of aself-expanding material like nitinol, and the tube can include severallongitudinal slits or slots that allow the tube to be expanded from anunexpanded, tubular shape, to an expanded shape as shown. Accordingly,the slit tube structure can be set to a desired shape, for example theillustrated expanded shape, by a heat set process. Alternatively theanchor can be formed from spring steel, alloys, or polymeric materialsas described elsewhere herein. The tether 104 can include an anchor wire111 (hidden behind a middle rib of the slit tube structure in FIG. 5C)extending through a runner tube 113. The anchor wire 111 can connect tothe anchor 102 at the distal joint 108. Similarly, the runner tube 113can connect to the anchor 102 at the proximal joint 108. Thus, awithdrawal or pulling load applied to the anchor wire 111 can lead tocompression of the anchor 102 between the distal joint 108 and theproximal joint 108. The compression can cause outward bowing andexpansion of the ribs 115 of the anchor 102. Accordingly, when actuatedwithin the anchoring vessel, the anchor 102 can secure the tetheringdevice 100 within the target anatomy.

FIG. 5D is a sectional view taken about line A-A of FIG. 5C of a distalportion of a tethering device. The anchor 102 can be a slit tubestructure having one or more rib segments extending longitudinallybetween the proximal joint 108 and the distal point 108. Each ribsegment 115 may have a distal end attached to the distal joint 108 and aproximal end attached to the proximal joint 108. In an implementation,the proximal joint 108 includes a tether collar 119, such as a band thatis swaged, glued, or otherwise affixed to one or more of the anchor 102or the runner tube 113 of the tether 104. The distal end of the anchor102 in any of the various implementations described herein can includean atraumatic distal tip 210 (see FIGS. 5C-5E).

FIG. 5E illustrates an interrelated implementation in which the anchor102 includes a braid or overlapping wire structure. The anchor 102 caninclude a braided mesh 120 made of self-expanding material such asnitinol such that the mesh structure can be set to a desired shape by,for example, a heat set process. As with other implementations, thetether 104 can include an anchor wire 111 extending through a runnertube 113 such that a withdrawal or pulling load applied to the anchorwire 111 can lead to compression of the anchor 102 between the distaljoint 108 and the proximal joint 108. The compression can cause outwardbowing and expansion of the braided mesh 120 to secure the tetheringdevice in the target anatomy.

The runner tube 113 can be large enough to provide a slip fit with theanchor wire 111, such that the anchor wire 111 is able to easily slidealong an entire length of the runner tube 113. Nonetheless, the runnertube 113 may be small enough to minimize a diameter of a tether lumen inthe guide-sheath, as will be described below. The runner tube 113 can befixed to the proximal joint 108 of the anchor 102, and can be longerthan a distance between the anchoring site and an exit port in thetetherable guide-sheath, but shorter than an overall length of theanchor wire 111 and the anchor lengths. Accordingly, the anchor wire 111can exit a proximal end of the runner tube 113. The runner tube 113 canhave a similar length to the pusher tube 109, or the runner tube 113 canbe shorter than the pusher tube 109, for example, to minimize an overalllength of the anchoring delivery system 10.

The pusher tube 109 can be large enough to provide a slip fit with therunner tube 113, such that the runner tube 113 is able to easily slidealong a length of the pusher tube 109. The pusher tube 109, however, maybe small enough to abut the tether collar 119 or a proximal end of theanchor 102. Accordingly, the pusher tube 109 can be pressed forward(and/or the anchor 102 withdrawn) such that a distal face of the pushertube 109 presses against the tether collar 119 (or proximal end of theanchor 102) to exert a forward load on the anchor 102. The pusher tube109 can be longer than an overall length of a delivery catheter, whichmay typically be 100 cm in length. Accordingly, the pusher tube 109 canbe grasped and pulled back after delivery of the anchor 102 to theanchoring site to remove the pusher tube 109 from the anchor 102, thetether 104 and the patient anatomy.

FIGS. 5F-5G illustrate a distal portion of an implementation of thetethering device 100. As previously described, a distal end of anelongated member such as the anchor wire 111 may be connected to adistal end of the anchor 102 at a distal joint 108. The connection canbe either permanent or temporary, e.g., like the transition describedabove. For example, the anchor wire 111 can be threaded into the distaljoint 108 of the anchor 102 such that it may be rotated to detach fromthe anchor 102. The anchor wire 111 can also be connected permanently tothe anchor 102 such as by soldering, welding, gluing, crimping or otherfasteners. The anchor 102 can be preloaded into a pusher tube 109 orconstricting sheath. The anchor 102 can be loaded during the procedureinto a catheter, which might have already been placed into thevasculature of a patient. The distal attachment point or joint 108between the anchor wire 111 allows the push force to be transmitted tothe distal portion of the anchor 102 such that the anchor 102 can be“pulled” into the pusher tube 109, which can significantly simplifyloading. When the anchor 102 is constricted by the pusher tube 109, oris inside a catheter, the distal end of the pusher tube 109 or thedistal end of the catheter can be positioned at the location where theanchor 102 is to be deployed. During deployment, the pusher tube 109 orthe catheter can remain stable and the anchor 102 can be pushed out,e.g. by applying a distal load to the runner tube 113. After the distalpart of the anchor 102 is in contact with an inner surface of theanchoring anatomy, the pusher tube 109 may be pulled back to allow theanchor 102 to expand into contact with the anchoring anatomy. In someimplementations, the anchor 102 has a closed cell structure and theanchoring structure will be constricted in its diameter as long as theanchor 102 is not fully released. This feature can significantlysimplify the release of the anchor 102 into the target anatomy.

As best shown in FIGS. 5F and 5G, the tethering device 100 can include astopper 122 attached to the anchor wire 111. The stopper 122 can limitan amount of expansion of the anchor 102. For example, when the anchorwire 111 is pulled back within the runner tube 113, the stopper 122 mayeventually contact a proximal end of the anchor 102 and/or the tethercollar 119, to prevent additional bowing of the rib segments 115. Atthat point, the anchor 102 can grip the anchoring vessel with sufficientfriction to resist being pulled proximally by the tether 104.Accordingly, the expansion of the anchor 102 may stop. A distancebetween the stopper 122 and the proximal end of the anchor 102 candefine the maximum expansion dimension of the anchor 102. Furthermore,the distance can correlate with a radial force applied to the anchoringanatomy by the anchor 102. Thus, the stopper 122 can be located to tunethe radial force and the corresponding fictional force applied to thetissue by the anchor 102. More particularly, the anchor 102 can beconfigured to apply sufficient frictional force to the tissue to resista pull force applied by an operator to the tether 104, or a reactionload applied to the tether 104 by a working device being advanced to atarget anatomy, as described below.

The anchors described herein are designed to stay fixed in a vessel whendeployed, but may slide through a catheter for delivery to the anchoringsite by pushing on the tether 104 and/or pusher tube 109 of the system.Additionally, the anchor 102 may be withdrawn into a capturing element,such as a tetherable guide-sheath 400, a micro catheter, etc., forremoval from the anatomy. Accordingly, pulling the anchor 102 into thecapturing element may retract and collapse the expandable structurerather than expand the expandable structure. Furthermore, the elongatedsection of the tethering device 100, i.e., the combination of the tether104 and the pusher tube 109, may be larger during delivery of the anchor102 to the anchoring site than after delivery. More particularly, afterdelivering the anchor 102, the pusher tube 109 may be removed from theanatomy to make the remaining portion of the elongated section, i.e.,the tether 104, as thin as possible such that the tetherableguide-sheath may be advanced over the tether 104 and fixed to the tether104 while maintaining a sufficiently large working lumen to advance aworking device through the tetherable guide-sheath to a target vessel.

The anchors described herein can include a structure configured toanchor within an anchoring vessel that relies upon apposition of aplurality of struts or rings with the underlying vessel. The anchorsdescribed herein can also include a structure configured to anchorwithin an anchoring vessel without relying upon apposition. For example,the anchors can incorporate a coiled wire having one or more loopsconfigured to be constrained to a straighter, low profile configurationduring delivery and upon release of the constraint take on a higherprofile configuration that is helical, spiral, twisted, bent, curved, ordouble-curved etc. such that the anchor anchors within the vessel, forexample, as shown in FIGS. 5H-5L, and as will be described in moredetail below.

FIG. 5H shows a detail view of a distal portion of a tethering device inaccordance with an implementation. The tethering device 100 can includean anchor 102 configured to deform or distort the vessel as opposed tovessel apposition devices, such as a stent-type anchor, which rely uponhigh radial force. Such anchors provide excellent holding force even ifdeployed in straight vessels. The anchor 102 provides simplicity inmanufacture, deliverability, anchoring even in relatively straightvessels, and speed of execution that is appealing from a clinicalstandpoint. The tethering device 100 can include an anchor 102 having ashape memory wire that passively changes (e.g. self-expands) from asmaller profile configuration to a larger profile configuration. Thetethering device 100 including the anchor 102 can be configured to beinserted into a vessel through a diagnostic catheter that accepts0.038-inch (0.97 mm) guide wires. As such, the anchor 102 may include awire segment, e.g., a segment of wire having a diameter of, e.g.,0.038-inch, that is formed from a shape memory wire, e.g., nitinol wire.The shape memory wire may be pre-formed into a heat set shape having oneor more primary and/or secondary curves, bends, coils, or turns. Theshape memory wire can include a heat set shape that includes, but is notlimited to, a J-shape, a hook-shape or other profile having one or morebends, curves, coils, etc. Furthermore, the shape memory wire may beelastically deflected into a substantially straightened or elongatedshape for delivery through a lumen of a catheter. Thus, the anchor 102may be delivered in the smaller profile configuration when the shapememory wire is straightened (as shown by dotted lines 125 in FIG. 5H),and the anchor 102 may change into the larger profile configuration whenthe wire returns towards the pre-set hook-shape 127 within the anchoringvessel. When the anchor 102 returns towards the resting shape inside thevessel, the vessel itself can undergo an amount of distortion and inturn engage the anatomy surrounding the vessel. Thus, the vesseldistortion and resistance provided by the anatomy adjacent the vesselcan contribute to the level of holding force provided by the anchor 102upon deployment in the anchoring vessel, as is described in more detailbelow.

FIG. 5I, a detail view of a distal portion of a tethering device, isshown in accordance with an implementation. As described above, thetethering device 100 having a self-expanding shape memory wire designmay include a preformed shape that incorporates one or more loops orcoils 126. More particularly, the anchor 102 can include a coil 126having one or more turns about an axis. For example, a longitudinalsegment 128 of the anchor 102 may be along the central axis and theturn(s) of the coil segment 126 may extend proximally from a distal endof the longitudinal segment 128 toward a proximal end of thelongitudinal segment 128. The proximal end of the longitudinal segment128 may, for example, be at the transition point 124 between the anchor102 and the anchor wire 111. The coil 126 can be a single loop, 1.5loop, or a 2 loop anchor 102. Each loop of the coil 126 can be a 6 mmloop.

The coil segment 126 may extend out of plane with a direction ofinsertion or in plane with a direction of insertion. FIGS. 5J-5L showanother implementation of an anchor 102 formed by an extension springconfigured to coil in plane with a direction of insertion. Thelongitudinal segment 128 of the anchor 102 can be along the central axisA. The coil(s) 126 can loop back toward a proximal end of thelongitudinal segment 128 and then back toward a distal end of thelongitudinal segment 128. Rather than the coil(s) 126 being about thecentral axis A, the coil(s) 126 can loop around an axis B that is at anangle to, such as perpendicular or orthogonal to, the central axis Aforming a pigtail type coil or spiral wire. The coils 126 in a restingstate, unconstrained by either a tubular element or vessel (i.e. in theair), can touch each other or align side-by-side (see FIG. 5K). Duringdelivery towards a vessel, the coils 126 are constrained in asubstantially straightened configuration, for example, within a tubulardelivery element. Withdrawal of the tubular delivery element in aproximal direction (arrow A in FIG. 5L), unsheathes the coils 126 anddeploys the anchor 102 in the vessel. When deployed within a vessel, thecoils 126 take on a helical, semi-helical, curved, or “wiggle” shapethat can distort the vessel and fix the anchor 102 to the deployedlocation. As described above, the return of the coils 126 towards thisshape following removal of a straightening constraint (e.g. lumen of afinder catheter through which the anchor 102 is delivered) can distortthe vessel from its natural path to a path that is dictated in part bythe shape the coils 126 take on upon unsheathing. For example, FIG. 5Millustrates an anchoring vessel 1904 following its natural path withinthe cerebral anatomy. FIG. 5N illustrates a tethering device 100deployed within the anchoring vessel 1904 where the anchor 102 of thetethering device 100 is a stent-like vessel apposition device. Theanchoring vessel 1904 generally maintains its natural path and anchoringis provided by the apposition of the anchor 102 against the vessel wallwith or without the presence of additional barbs or cleats or otherfeature to improve fixation of the anchor 102. FIG. 5O illustratesanother implementation of a tethering device 100 deployed within theanchoring vessel 1904. In this implementation, the anchor 102 takes on asubstantially helical shape within the anchoring vessel 1904, which inturn, causes the anchoring vessel 1904 to distort away from its naturalpath and instead follow the directional turns of the anchor 102. In thisimplementation, engagement between the distorted vessel 1904 and thetissues of the adjacent anatomy assist in the holding force provided bythe anchor 102. The distortion within the surrounding tissue allows theresistance of the surrounding tissue to these distortions to increasethe hold of the anchor 102 such that the anchor 102 now engages anentire “block” of tissue rather than just the vessel wall. The holdingforce provided can be sufficient to prevent the anchor 102 from beingdislodged from the anchoring vessel 1904 upon application of a pullingforce on the tether 104 in a proximal direction even when tightly drawnand coupled to the proximal end of the guiding sheath 400 such thatadvancement of a working device causes a downward pulling force on thesheath 400.

The wire composition and size, as well as the coil diameter, the numberof coils, and the amount of expected external force on the anchor 102can all be considered in the design of the anchor 102. FIG. 5K shows twocoil segments 126 to the anchor 102, however, the anchor 102 can includeone, two, three, four, five, six, or more coil segments 126. Thediameter of the coils 126 can vary depending on the vessel within whichthe anchor device is intended to be used. The diameter of the coils 126can affect the holding force as the smaller the coil loop, generally thestiffer the anchor.

The tethering device 100 can include the tether 104 extending proximallyfrom the anchor 102. In an implementation, the tether 104 may have asmaller diameter than the shape memory wire used to form the anchor 102.In some implementations, the tether 104 can be formed from a shapememory wire having a diameter between about 0.005-inch to about0.014-inch, e.g., 0.006-inch, 0.007 inch, 0.008 inch, or 0.009-inch upto 0.016-inch. In other implementations, the tether 104 can have adiameter from about 0.005 inches to 0.025 inches, e.g., 0.008 inches, or0.009 inches, or 0.010 inches, or 0.035 inches, depending on the degreeof support that the tether 104 provides. The tether 104 can be a solidwire rod, a ribbon, or a hypotube. In some implementations, the tether104 can be a stainless steel rod, ribbon or hypotube. In otherimplementations, the tether 104 can be Drawn Filled Tubing (DFT) with aradiopaque core, such as an outer sheath of a composite to providestrength and a core material to provide superelasticity, conductivity,radiopacity, resiliency, etc. In some implementations, the tether 104can be DFT of Nickel titanium with a radiopaque core such as platinum ortantalum.

The tether 104 may be integrally formed with the anchor 102, e.g., theanchor 102 and the tether 104 may be segments of a same wire.Alternatively, the anchor 102 and the tether 104 may be different wiresthat are connected at a transition point 124 via a mechanical, adhesive,or welded bond. In some implementations, the wire of the tether 104 isintegral with the wire of the anchor 102 and the anchor 102 created bycoiling over a mandrel and/or via grinding. For example, in someimplementations the anchor 102 can be formed by winding the wire arounda shaft such as a mandrel. The ends of the anchor 102 can be bent into adesired shape, whether that is straight or otherwise looped, hooked, orbent. The anchor 102 can be formed by cold winding or hot winding andthen hardened to relieve stress and allow resilience in the spring. Theanchor 102 can be formed by coiling a length of wire around a mandrel Min a first direction (arrow A in FIG. 5P) and doubling back around themandrel M in a second opposition direction (arrow B in FIG. 5Q) tocreate a first overlap section. More overlap sections can be created byonce again coiling the wire about the mandrel M in the first direction(arrow A in FIG. 5R) until a coil having a particular holding strengthis formed. More coils can be formed in the length of wire in a similarmanner until an anchor 102 is formed having the desired number of coilshaving a desired overall diameter and a desired holding force. Theanchor 102 can also be formed by grinding a round or flat wire using acoiling lathe to create single diameter coils or tapered coils. Theanchor 102 can be formed of a plurality of materials including a corewire and an external coil laser welded to the core wire. The anchor 102can be formed of stainless steel wire, nitinol wire, drawn filled tube(DFT) with a radiopaque core, hypotube.

One skilled in the art will appreciate that a shape memory wire may bepre-formed to have numerous larger profile configuration shapes. Forexample, the coil segment 126 of the anchor 102 may extend distally fromthe longitudinal segment 128 of the anchor 102 with turns havingincreasing diameters such that a conical coil shape is formed.Alternatively, the turn diameters may increase and decrease in alongitudinal direction of the coil segment 126 such that a barbellshaped coil segment is formed. Still further, the coil segments 126 mayeach have a diameter that are substantially the same and sized to engagethe vessel within which the anchor 102 is implanted upon release fromthe catheter lumen. Thus, the anchor 102 may include a shape memory wiresegment that may be deformed or deflected to the smaller profileconfiguration and then released into a heat set shape of the largerprofile configuration to create friction against a vessel wall. Thelarger profile configuration of the anchor 102 may be wider in atransverse dimension than the smaller profile, and thus, the anchor 102may press against a vessel wall to anchor the tethering device 100 whenit emerges from the lumen of the catheter.

FIGS. 5S-5U illustrate various implementations of a distal end of atethering device 100. The anchor 102 can include one or more shockabsorber regions 123 and one or more anchoring loop regions 129. FIG. 5Sillustrates an anchor 102 having a wire coiled into a distal shockabsorber region 123 adjacent a central anchoring loop region 129 whereasFIG. 5T illustrates a distal anchoring loop region 129 having a floppyJ-tip 131. FIG. 5U illustrates an anchor 102 having a wire coiled into adistal anchoring loop region 129 and a proximal anchoring loop region129 interspersed with a first shock absorber region 123 and a secondshock absorber region 123, thus creating two sets of anchoring loops 129and two sets of absorbent loops 123.

The anchor 102, with or without additional barbed or cleat elements, canembed within the wall of the vessel and optionally can cause the vesselwithin which it is deployed to undergo a degree of distortion,particularly if a proximal tugging force is applied on the tether 104.Thus, the friction between the anchor 102 and the vessel aids in theretention of the tethering device in the vessel as does the distortionof the vessel within which the tethering device is anchored, andoptionally engagement between barbs of the anchor and the vessel. Thevessel can deform into a single or double curve under the distortionforce of the anchors 102 described herein further improving theiranchoring function while maintaining flow through the anchor 102 withlittle disturbances due to the presence of the anchor 102. Thus, acombination of forces provides an anchoring function. The combination ofproficient anchoring for the delivery of implant delivery systems andmaintenance of blood flow in and around the anchor are beneficial tosuccessful interventions within the neurovasculature and consistentaccess catheter delivery to the skull base.

It should be appreciated that the anchor itself need not embed withinthe wall of the vessel due to a shape change upon deployment. In someimplementations, the anchor 102 is deployed in a more superficialanatomic location, such as within a facial artery, that allows forfixation of the anchor 102 from outside the body anatomy. For example,the tethering device 100 can include a proximal tether 104 and a distalanchor 102 deployed within a superficial vessel. The distal anchor 102can be fastened within the superficial vessel by magnetic attractionbetween the distal anchor 102, formed of a magnetic material such asstainless or incorporating magnetic elements, and one or more magnetsplaced on a skin surface near the superficial vessel, such as on thecheek or the neck near the ear. In other implementations, at least aportion of the anchor 102 can be externalized and clamped outside thebody.

It should be appreciated that various anchor implementations aredescribed herein and the term anchor is used generally herein to referto an element used for anchoring of the tethering device within a targetanatomy. Anchors can include any of a variety of configurations asdescribed herein including, but not limited to self-expanding ornon-self-expanding devices, braids, mesh, wires, stents, coils, or otherparticular implementation described herein. Any of a variety ofcombinations of features of the anchors are considered herein. Further,although a particular anchor implementation may be shown in a particularfigure for purposes of illustration, it is not intended to be limitingor to suggest that the anchor implementation shown would be the onlyanchor implementation useful for that particular feature.

The deployment of the various anchoring devices described herein willnow be described. It should be appreciated that the anchor shown in thefigure is represented in schematic for illustration purposes only torepresent a change from a low profile configuration to a higher profileconfiguration. The actual configuration of the anchor can vary asdescribed herein.

Referring to FIGS. 6A-6B, a schematic view of a tethering devicedeployment is illustrated in accordance with an implementation. Thetethering device 100 can include a distal anchor 102, a proximal tether104 having an inner anchor wire 111 and an outer runner tube 113. Whendeploying the tethering device 100, the operator may fix the runner tube113 in place and adjust the placement of the anchor 102 in the vessel.The anchor 102 can be expanded and the anchoring can be tested bypulling the anchor wire 111 relative to the runner tube 113 and thenfixing the two in relative position to each other (see FIG. 6B). Thetethering device 100 can be adjustable, for example, if there is slip oran “extreme” moment during the procedure extra anchoring can betransiently applied to the anchoring vessel and released when thedistension applied to the vessel is not desired. The expansion appliedby pulling the anchor wire 111 can be in addition to expansion providedby self-expansion of the anchor 102 to a preformed expanded shape, forexample as shown in FIGS. 2B-2D or FIGS. 5A-5B. If the runner tube 113and anchor wire 111 interaction provides some friction the expansion ofthe anchor 102 can be retained from the friction between the twosystems. It can provide anchoring that allows the deployment of theguide-sheath over the tether 104, i.e., the runner tube 113/anchor wire111 combination, as will be described in more detail below.

Referring to FIG. 7A, a schematic view of a tethering device deploymentis illustrated in accordance with an implementation. Once tetherableguide-sheath 400 is positioned, another adjustment of the runner tube113 relative to the anchor wire 111 can be done, and then the anchorwire 111 can be locked in place relative to the tetherable guide-sheath400. Referring to FIG. 7B, a schematic view of a tethering devicedeployment is illustrated in accordance with an implementation. In animplementation, when the fixation point is applied to the anchor wire111, downward forces on the tetherable guide-sheath will transmitdirectly to the anchor wire 111 and in return will expand the anchor 102as the distal tip is pulled downward with downward force—furtheranchoring the system in response to downward force. It is expected thatduring the procedure, as long as the anchor wire 111 fixation relativeto the tetherable guide-sheath 400 is constant, the anchor 102 willexpand and anchor in accordance with the forces that are transmitteddownward on the tetherable guide-sheath 400. Increasing or decreasing“baseline anchoring” can be dialed into the system in accordance withoperator preferences and the needs of the procedure. The baselineanchoring may also be applied by self-expansion of the anchor 102 to apreformed expanded shape as shown in FIGS. 5D-5F.

Referring to FIG. 8A, a schematic view of a tethering device in anunexpanded state is illustrated in accordance with an implementation.Taking this to a more mechanical level, one or more locking elements 130may be used to “open and close” the anchor 102 at different diameters(and corresponding tensions against the vessel wall). The anchor 102 isshown in a low-profile configuration with the anchor 102 cut away sothat the anchor wire 111 traversing the entire length of the assembly isvisible within the anchor 102 and exiting the proximal end of the runnertube 113. Specialized locking elements 130 can be applied individuallyto the portions of the anchor wire 111 and the runner tube 113 that areexposed, e.g., that are situated outside of a patient anatomy and/or arotating hemostatic valve (RHV) coupled with the tetherableguide-sheath, as described below. For example, a first locking element130 a can be coupled to the anchor wire 111 and a second locking element130 b can be coupled to runner tube 113.

Referring to FIG. 8B, a schematic view of a tethering device in anexpanded state is illustrated in accordance with an implementation. Withtightened down locking elements 130 a, 130 b, the relationship of theanchor wire 111 to the runner tube 113 can be adjusted—either adjustedto tactile feedback or perhaps to fluoroscopic visualization of theexpansion and contraction of the anchor. Tension can be applied bypulling the two locking elements 130 a, 130 b apart to expand the anchor102. The reverse can be used to contract the anchor 102 and may even beheld contracted to withdraw the device into a catheter or sheath.

Referring to FIG. 8C, a schematic view of a tethering device in anexpanded state and locked state is illustrated in accordance with animplementation. Once the desired tension is applied to expand the anchor102 to a target dimension for anchoring at an anchoring site in ananchoring vessel, the anchor wire locking element 130 a can be advancedforward to abut a proximal end of the runner tube 113. Holding theanchor wire locking element 130 a firm against the runner tube 113 atthe anchor wire/runner tube transition and locking the anchor wirelocking element 130 a down at that position can lock the relationship ofthe anchor wire 111 and the runner tube 113 relative to each other (andlock the anchor 102 under a fixed tension). This is “locking open” theanchor 102. For added security, the runner tube locking element 130 bcan be loosened and advanced to the face of the RHV and/or thetetherable guide sheath, and locked down to prevent movement of therunner tube 113 relative to the RHV/tetherable guide-sheath assembly. Ifthe RHV being used is not “specialized” to hold the runner tube 113firmly, there can be a risk of slippage. If the runner tube 113 is of astainless steel or nitinol or hardened material, when the operatorencounters resistance on advancing interventional tools and anchoring iscalled for a downward force can be transmitted from the tetherableguide-sheath down the column of the tether 104, for example, formed bythe anchor wire 111 extending through the runner tube 113. A standardcommercial RHV can slip, and thus, a tether gripper such as aspecialized RHV may be used to reinforce the relationship of the tether104 relative to the sheath assembly and is described in more detailbelow (see FIGS. 25-27).

As described herein the tethering device can vary in its pushability,steerability, torque and opacity. Thus, in some implementations thetethering device 100 can have a relatively pushable tether 104 such thatthe tethering device 100 can be advanced through a guide catheter. Inother implementations, the tethering device has a tether 104 that isless pushable to advance and steer the anchor 102 into place. Thus, apusher tube 109 or other tubular element 135 configured to receive thetether 104 may be incorporated to aid in the delivery of the anchor 102to the target site through a catheter lumen. FIGS. 9A-9B illustrate aschematic view of a tethering device 100 having an anchor 102 configuredto be elastically deformed into a low profile configuration. In thelow-profile configuration, the coil segments 126 of the anchor 102coupled at a distal end region of the tether 104 are extended orsubstantially straightened into a smaller profile configuration such asthose shown by dotted lines in FIGS. 5H-5I such that the anchor 102 canbe positioned within a tubular element 135 (see FIG. 9A). A pusher tube109 can be positioned over the tether 104 and within the tubular element135 such that a distal end of the pusher tube 109 abuts a proximal endof the anchor 102 to aid in the delivery of the anchor 102 at the targetlocation. In order to release the anchor 102 into the higher-profileconfiguration, the tubular element 135 can be withdrawn in a proximaldirection (arrow A) and/or the pusher tube 109 advanced in a distaldirection (arrow B) urging at least a portion of the anchor 102 to exitthe tubular element 135 prior to unsheathing the anchor 102 from thetubular element 135 such that the anchor 102 emerges from the lumen ofthe tubular element 135 and self-expand or otherwise return to a largerprofile configuration to anchor within a vessel (see FIG. 9B). Thepusher tube 109 can have an outer diameter between that of the tether104 and the anchor 102, for example an outer diameter of 0.006-inch to0.038 inch, e.g. 0.021-inch. As described elsewhere herein, one or morelocking elements 130 can be coupled to the tether 104, the tubularelement 135, and/or a portion of the pusher tube 109 and situatedoutside of a patient anatomy and/or a rotating hemostatic valve (RHV)coupled with a proximal end of the tetherable guide-sheath. Further, asdescribed elsewhere herein, the anchor 102 can be re-sheathed such as byadvancing the tubular element 135 in a distal direction, pulling thetether 104 in a proximal direction, or both such that the anchor 102abuts a distal end of the tubular element 135 and gradually straightensas the anchor 102 is pulled into the tubular element 135 (FIG. 9C).

As described above, the anchor 102 can incorporate one or more struts202 having free, distal strut ends 204. As shown in FIGS. 10A-10C, thestrut ends 204 can form cleats 205 that protrude outwards upon expansionor release of the struts 202 form their constrained configuration suchthat the pointed ends 204 of the cleats 205 can engage with the vesselwall. The cleats 205 can undergo flexure upon sheathing and re-sheathingsuch that they can be removable from the vessel. FIG. 10A shows thestruts 202 in a constrained configuration such that the cleats 205 andtheir pointed ends 204 are contained within a tubular element 135. Uponretraction of the tubular element 135 in a proximal direction (arrow A)and/or extension of the struts 202 in a distal direction (arrow B), thestruts 202 and associate cleats 205 are released from constrainingforces (FIG. 10B). The struts 202 can flex in a direction away from thelongitudinal axis of the tubular element 135 and the associated cleats205 can flex or bend such that their pointed ends 204 extend towards thevessel wall. In some implementations, the cleats 205 upon release fromthe constraint of the tubular element 135 can take on a curved shapesuch that their pointed ends 204 are oriented in a direction back towarda proximal direction (see FIG. 10B). As such, the cleats 205 can allowfor distal movement within the vessel, but are prevented from movingproximally within the vessel due to the pointed ends 204 of the cleats205 snagging on the vessel wall. The pointed ends 204 of the cleats 205can be urged away from the vessel wall during re-sheathing, for exampleby advancing the tubular element 135 in a distal direction such that thepointed ends 204 of the cleats 205 flex back towards the longitudinalaxis and the struts 202 are constrained in the lower profileconfiguration within the tubular element 135 (see FIG. 10C). FIGS.10D-10E illustrate another implementation of cleats 205 that can springout upon withdrawal of or advancement from a tubular element 135.

Tetherable Guide-Sheath

As mentioned above, the anchoring delivery system 10 can include atethering device 100 configured to be used with a guide-sheath tosupport and guide working devices such as implant delivery systems to atarget anatomy. FIG. 11 shows a perspective view of an implementation ofa tetherable guide-sheath 400. The tetherable guide-sheath 400 can be anover-the-wire (OTW) type device and include an elongated body 402extending from a proximal furcation 404 at a proximal end region 403 toa tip 406 at a distal end configured to bluntly dissect through anddilate narrowed sections of a diseased vessel as it is advanced. Theproximal furcation 404 may include several lumens molded into aconnector body to connect to corresponding lumens of the body 402 of thetetherable guide-sheath 400. For example, the body 402 and the proximalfurcation 404 may include a respective tether lumen 408 and a respectiveworking lumen 410. The proximal furcation 404 may also includeadditional lumens, e.g., an optional lumen 412, that can be connected toa corresponding lumen of the body 402 to serve a purpose other thanreceiving the tether 104 of the tethering device 100 or receiving aworking device 802 to be delivered to a target anatomy. For example, theoptional lumen 412 may be connected with a syringe to deliver contrastthrough a contrast lumen in the body 402 toward the tip 406 and into thetarget anatomy. A segment of the tether lumen 408 can bifurcate awayfrom a segment of the working lumen 410. More particularly, the segmentof the tether lumen 408 may extend at an angle from the segment of theworking lumen 410 to create a separation between the tether proximalport 414 and the working proximal port 416. The tether lumen 408 canextend from the tether distal port 504 at a distal end to a tetherproximal port 414 of the proximal portion 403 of the elongated body 402.Similarly, the working lumen 410 can extend from a distal end to aworking proximal port 416 of the proximal portion 403 of the elongatedbody 402.

The furcation 404 can be coupled to a rotating hemostatic valve (RHV)434. As mention above, the furcation 404 can include an optional lumen412 that may be connected with a syringe via a connector 432 to delivera forward drip, a flush line for contrast or saline injections through alumen in the body 402 toward the tip 406 and into the target anatomy.The optional lumen 412 can also connect to a large-bore aspiration lineand an aspiration source (not shown) such as a syringe or pump to drawsuction through the working lumen 410, as described in the U.S. PatentApplication, filed Jul. 22, 2016, which is incorporated herein byreference. The furcation 404 can be constructed of thick-walled polymertubing or reinforced polymer tubing. The RHV 434 allows for theintroduction of devices through the guide-sheath 400 into thevasculature, while preventing or minimizing blood loss and preventingair introduction into the guide-sheath 400. The RHV 434 can include aflush line or connection to a flush line so that the guide-sheath 400can be flushed with saline or radiopaque contrast during a procedure.The flush line can also be used as a second point of aspiration. The RHV434 can be integral to the guide-sheath 400 or the guide-sheath 400 canterminate on a proximal end in a female Luer adaptor to which a separatehemostasis valve component, such as a passive seal valve, a Tuohy-Borstvalve or rotating hemostasis valve may be attached. The valve 434 canhave an adjustable opening that is open large enough to allow removal ofdevices that have adherent clot on the tip without causing the clot todislodge at the valve 434 during removal. Alternately, the valve 434 canbe removable and is removed when a device is being removed from thesheath 400 to prevent clot dislodgement at the valve 434. The furcation404 can include various features of the proximal components described,for example, in U.S. application Ser. No. 15/015,799, filed Feb. 4,2016, which is incorporated herein in its entirety. The systemsdescribed herein can provide advantages from a user-standpoint overtri-axial systems in that they can be safely used by a single user.Common tri-axial systems have multiple RHV—one for each componentinserted. The positional location of the various components on thetable, from left to right, inform users of which component it is. Forexample, components positioned to a right side of the table are insertedmore distally and components positioned to the left side of theoperating table are inserted more proximally. The space on the tablemust be quite large (e.g. up to 210 cm-220 cm long). Generally all thecomponents are arranged in this way and require an additional technicianto organize and arrange the various components. The systems describedherein incorporate components inserted through a single RHV. As such,rather than relying on a positional organization spread out across atable over 6 feet long, multiple components of the systems describedherein extend through the same RHV such that a single user can controldelivery, all the components can be shorter, and can be used with lessrisk of sterile field contamination.

The length of the elongated body 402 is configured to allow the distaltip 406 of the body 402 to be positioned as far distal as thebifurcation between the external carotid artery (ECA) and the internalcarotid artery (ICA), for example, from a transfemoral approach withadditional length providing for adjustments if needed. In someimplementations, the length of the body 402 can be in the range of 80 to90 cm or up to about 100 cm or up to about 105 cm. In implementations,the body 402 length is suitable for a transcarotid approach to thebifurcation of the carotid artery, in the range of 20-25 cm. In furtherimplementations, the body 402 length is suitable for a transcarotidapproach to the CCA or proximal ICA, in the range of 10-15 cm. The body402 is configured to assume and navigate the bends of the vasculaturewithout kinking, collapsing, or causing vascular trauma, even, forexample, when subjected to high aspiration forces.

Referring to FIG. 12A, a detail view, taken from Detail B of FIG. 11, ofa distal end of a tetherable guide-sheath is illustrated in accordancewith an implementation. The tip 406 of the tetherable guide-sheath 400can have a same or similar outer diameter as a section of the body 402leading up to the distal end. Accordingly, the tip 406 may have a distalface 502 orthogonal to a longitudinal axis passing through the body 402and the distal face 502 may have an outer diameter substantially equalto a cross-sectional outer dimension of the body 402. In animplementation, the tip 406 includes a chamfer, fillet, or taper, makingthe distal face 502 diameter slightly less than the cross-sectionaldimension of the body 402. In a further implementation, the tip 406 maybe an elongated tubular portion extending distal to a region of the body402 having a uniform outer diameter such that the elongated tubularportion has a reduced diameter compared to the uniform outer diameter ofthe body 402 (see FIGS. 12C-12E). Thus, the tip 406 can be elongated orcan be more bluntly shaped. Accordingly, the tip 406 may be configuredto smoothly track through a vasculature and/or to dilate vascularrestrictions as it tracks through the vasculature. In an implementation,the tether lumen 408 may have a distal end forming a tether distal port504 in the distal face 502. Similarly, the working lumen 410 may have adistal end forming a working port 506 in the distal face 502. As will bedescribed below, the tetherable guide-sheath 400 may also include one ormore tether entry ports 504 along a side of the body 402.

Referring to FIG. 12B, a detail view, taken from Detail B of FIG. 11, ofa distal end of a tetherable guide-sheath is illustrated in accordancewith an implementation. The tetherable guide-sheath 400 may include atip 406 that tapers from a section of the body 402 leading up to thedistal end. That is, an outer surface of the body 402 may have adiameter that reduces from a larger dimension to a smaller dimension ata distal end of the tether lumen 408, i.e., at the tether distal port504. For example, the tip 406 can taper from an outer diameter ofapproximately 0.114″ to about 0.035″. The angle of the taper of the tip406 can vary depending on the length of the tapered tip 406. Forexample, in some implementations, the tip 406 tapers from 0.110″ to0.035″ over a length of approximately 50 mm. In an implementation, thetether distal port 504 is centered along a longitudinal axis passingthrough the body 402. Thus, the tapered tip 406 may be concentricallydisposed around the tether distal port 504. Accordingly, the tapered tip406 may track smoothly around bends within the targeted anatomy to avoidcausing trauma to the tissue. The working lumen 410 may extend parallelto the tether lumen 408 through the body 402 to a mouth 508 locatedproximal to the tether distal port 504 near the distal end of thetetherable guide-sheath 400. More particularly, the working port 506 maybe an elongated mouth 508 disposed in a side surface of the body 402,for example proximal to the tip taper. The mouth 508 may be formed inthe side surface using manufacturing techniques such as skiving and/ordrilling. Thus, the mouth 508 may have a dimension in at least onedirection that is larger than a diameter of the working lumen 410. Forexample, the mouth 508 may have a longitudinal dimension that is largerthan a cross-sectional diameter of the working lumen 410. The diameterof the mouth 508 can be at least 1.5×, 2×, 2.5×, or 3× as large as anouter diameter of a working device 802 extending therethrough. The mouth508 can be skived such that it has a length from a proximal end to adistal end that allows for a working device 802 to exit at a range ofangles, for example, very nearly parallel to the body 402 to a positionthat is at an angle to the body 402, for example substantiallyperpendicular as well as greater than a right angle to the body 402.This arrangement allows for ease of delivery of a working device 802through the mouth 508 even in the presence of a severe angulation withinthe vessel being traversed or where a bifurcation is present. Often,tortuous segments in vessels and bifurcations have severe angulations to90° or greater angle up to 180°. Classic severe angulation points in thevasculature can include the aorto-iliac junction, the left subclavianartery takeoff from the aorta, the brachiocephalic (innominate) arterytakeoff from the ascending aorta as well as many other peripherallocations. A distal tip 406 can extend well beyond a distal end of themouth 508 such that the tip 406 forms an elongate, soft tip formaneuvering through the turns of the vasculature (see, e.g., FIGS.12C-12D). In some implementations, the mouth 508 can be located justproximal to the tip 406 or can be located at least 0.25 mm or more awayfrom the tip 406.

In an implementation, the tetherable guide-sheath 400 includes one ormore radiopaque markers 510. The radiopaque markers 510 can be disposednear the mouth 508. For example, a pair of radiopaque bands may beswaged, painted, embedded, or otherwise disposed in or on the body 402,for example on either side of the mouth 508. In some implementations,the radiopaque markers 510 include a barium polymer, tungsten polymerblend, tungsten-filled or platinum-filled marker that maintainsflexibility of the distal end of the device and improves transitionalong the length of the guide-sheath 400 and its resistance to kinking.In some implementations, the radiopaque marker 510 is a tungsten-loadedPEBAX or polyurethane that is heat welded to the body 402. The markers510 are shown in the figures as rings around a circumference of one ormore regions of the body 402. However, the markers 510 can have othershapes or create a variety of patterns that provide orientation to anoperator regarding the position of the mouth 508 within the vessel.Accordingly, an operator may visualize a location of the mouth 508 underfluoroscopy to confirm that the mouth 508 is directed toward a targetanatomy where a working device 802 is to be delivered. For example,radiopaque marker(s) 510 allow an operator to rotate the body 402 of thetetherable guide-sheath 400 at an anatomical access point, e.g., a groinof a patient, such that the mouth 508 provides access to an ICA bysubsequent working device(s), e.g., catheters and wires advanced to theICA. In some implementations, the radiopaque marker(s) 510 includeplatinum, gold, tantalum, tungsten or any other substance visible underan x-ray fluoroscope. In various implementations, the distance from thetether distal port 504 to the mouth 508 should be in a range thatfacilitates maneuvering of subsequent devices advanced through mouth508. It should be appreciated that any of the various components of thesystems described herein can incorporate radiopaque markers as describedabove.

Referring to FIG. 13, a sectional view of a distal end of a tetherableguide-sheath is illustrated in accordance with an implementation. In animplementation, the tetherable guide-sheath 400 includes the tip 406 atthe distal face 502 of the body 402. Thus, FIG. 13 may be across-sectional view of the distal end of the tetherable guide-sheath400 illustrated in FIG. 12A and described above. The working lumen 410and the tether lumen 408 can extend longitudinally along respective axesbetween the proximal end 403 of the tetherable guide-sheath 400 and thedistal tip 406. Furthermore, the tether lumen 408 may include more thanone tether distal port 504. For example, a tether distal port 504 mayoptionally be disposed in the distal face 502 of the body 402, and oneor more additional tether entry ports 504 may be disposed in a sidesurface of the body 402, such that the ports are in fluid communicationwith the tether lumen 408. More particularly, several tether entry ports504 may be disposed in the side surface at regularly spaced intervals.The tether 104 may be inserted through any of the tether entry ports 504into the tether lumen 408 to allow the tip 406 of the tetherableguide-sheath 400 to be advanced into a same or a different anatomy thanthe anatomy that the anchor 102 is deployed within. For example, thetether 104 may be disposed in an anchoring vessel and the tip 406 of thetetherable guide-sheath 400 may be advanced into a target vessel thatbifurcates away from the anchoring vessel. As such, it will berecognized that depending on the tether distal port 504 through whichthe tether 104 is placed, a different length of the tetherableguide-sheath 400 may be advanced into the target anatomy. For example,when the tether 104 is placed in the most distal tether distal port 504in the side surface, a distal segment of the tetherable guide-sheath 400between the utilized tether distal port 504 and the tip 406 may beadvanced into the target anatomy. When the tether 104 is placed in themost proximal port in the side surface, however, the distal segment ofthe tetherable guide-sheath 400 between the utilized tether distal port504 and the tip 406 may be longer. Accordingly, a stump tip of thetetherable guide-sheath 400 as that shown in FIG. 12A or a long tip ofthe tetherable guide-sheath 400 as shown in FIGS. 12C-12D may beadvanced into the target anatomy.

Referring to FIG. 14, a sectional view, taken about line A-A of FIG.12B, of a distal end of a tetherable guide-sheath is illustrated inaccordance with an implementation. In an implementation, the tetherableguide-sheath 400 includes the mouth 508 on a side surface of the body402. The working lumen 410 and the tether lumen 408 may extend in alongitudinal direction through at least a portion of the tetherableguide-sheath 400. For example, the working lumen 410 may extend along alongitudinal working axis 702 between the proximal furcation 404 and themouth 508. Similarly, a proximal tether lumen 704 having a segmentextending proximal to the mouth 508 may extend along a longitudinaltether axis 706 from the proximal furcation 404 (in the case of an OTWtetherable guide-sheath 400) and/or an exit port (in the case of arapid-exchange (RX) type of tetherable guide-sheath 400 as describedbelow). The lumens need not, however, extend longitudinally over theentire length of the tetherable guide-sheath 400. For example, a distaltether lumen 708 segment may be directed radially inward from theproximal tether lumen 704 over a portion of the tetherable guide-sheath400 distal to the mouth 508. More particularly, the tether lumen 408 maydiverge from the longitudinal direction toward the tether distal port504, which may be centrally located relative to a cross-section of thebody 402. Thus, the tether axis 706 passing through the tether distalport 504 may be radially offset from the tether axis 706 passing throughthe proximal tether lumen 704. The tether axis 706 passing through thetether distal port 504 may pass through the working lumen 410 at alocation proximal to the mouth 508, i.e., the tether distal port 504 maybe longitudinally aligned with the working lumen 410. In animplementation, the tether axis 706 passing through the tether distalport 504 may be coaxial with the working axis 702, or may be closer tothe working axis 702 then to the tether axis 706 extending through theproximal tether lumen 704.

In an implementation, the working lumen 410 extends along a deflectingsurface 710 that directs a working device 802 passing distally throughthe body 402 outward through the mouth 508. More particularly, theworking lumen 410 may extend from the mouth 508 at the tip 406 of thetetherable guide-sheath 400 to a proximal end 403 of the tetherableguide-sheath 400, and the tetherable guide-sheath 400 may include adeflecting surface 710 between the working lumen 410 and the tetherlumen 408. The deflecting surface 710 may be oblique to the workinglumen 410. That is, the deflecting surface 710 may include a ramp havinga radius that provides a smooth distal transition from the working axis702 to an exit axis extending radially outward through the mouth 508.The exit axis may be at an angle to the working axis 702, for example, a10, 15, 20, 25, 30, 35, 40, or 45 degree angle. In some implementationsthe exit axis is at a 30° angle.

As described above, the body 402 of the tetherable guide-sheath 400 mayinclude at least one lumen, and may include several lumens. Moreparticularly, the implementations depicted in FIGS. 12-14 are dual-lumencatheters having a working lumen 410 accompanied by a tether lumen 408along a majority of a length of tetherable guide-sheath 400. A diameterof tether lumen 408 may be less than a diameter of working lumen 410.Furthermore, the diameter of tether lumen 408 may vary. For example, thetether lumen 408 may have a diameter large enough to receive the tether104, but not large enough to receive the anchor 102 of the tetheringdevice 100. Alternatively, the tether lumen 408 may have a diameterlarge enough to receive the anchor 102 over at least a portion of alength of the tether lumen 408, e.g., to allow the anchor 102 to bepushed or pulled through the tether lumen 408. The tether lumen 408 mayalso have a diameter large enough to receive the anchor 102 when theanchor 102 is urged into a lower profile configuration such that it canbe received within at least a portion of the tether lumen 408.

According to some implementations, the tether lumen 408 is independentof the working lumen 410, and the working lumen 410 runs the entirelength of tetherable guide-sheath 400. In some implementations, thetetherable guide-sheath 400 will have performance characteristicssimilar to other sheaths used in carotid access and AIS procedures interms of kinkability, radiopacity, column strength, and flexibility. Theworking lumen 410 may deliver a working device toward the anchor 102,and the working device may be directed to the deflecting surface 710 tosmoothly exit at an angle to the longitudinal axis of the working lumen410. Furthermore, the mouth 508 of the tetherable guide-sheath 400 maybe wider than the internal diameter of the working lumen 410 so as toallow a wide range of exit angles of a working device exiting thetetherable guide-sheath 400. According to some implementations, theexiting working device can run almost parallel with the tetherableguide-sheath 400 to greater than 90 degrees, which severely angulatedarteries may require. Exit angles from the mouth 508 of the tetherableguide-sheath 400 should consider the variety of angles that the anatomymay require.

FIG. 15A illustrates a perspective view of an implementation of atetherable guide-sheath 400. As with other implementations, thetetherable guide-sheath 400 can include an elongated body 402 containingone or more lumens extending from a distal end to a proximal portion.For example, a tether lumen 408 may extend from a tether distal port 504at a tip 406 of the tetherable guide-sheath 400 to a tether proximalport 414 of the proximal portion 403. Similarly, a working lumen 410 mayextend from a mouth 508 of the tip 406 to a working proximal port 416 ofthe proximal portion 403. The tetherable guide-sheath 400 may include aproximal furcation 404 in the proximal portion 403 where a segment ofthe tether lumen 408 bifurcates away from a segment of the working lumen410. More particularly, the segment of the tether lumen 408 may extendat an angle from the segment of the working lumen 410 to create aseparation between the tether proximal port 414 and the working proximalport 416. One or more of the tether proximal port 414 or the workingproximal port 416 may incorporate a tether gripper 1502 (see FIGS.25-27).

Referring to FIG. 15B, a detailed sectional view taken from Detail B ofFIG. 15A, of a distal portion of a tetherable guide-sheath isillustrated in accordance with an implementation. In an implementation,the tetherable guide-sheath 400 may include a chamber 515 locatedproximal to the tether distal port 504 in the tip 406. The chamber 515may be sized to receive the anchor 102 of the tethering device 100. Forexample, the tether distal port 504 may be chamfered, i.e., having adistal port diameter that is larger than a proximal port diameter, suchthat the proximal joint 108 of the tethering device 100 moves smoothlyinto the tether distal port 504 when the tetherable guide-sheath 400 isadvanced over the anchor 102. The tether distal port 504 may expandslightly to receive the anchor 102. Furthermore, the anchor 102 may beretracted into the chamber 515 to store the anchor 102. Thus, in animplementation, the chamber 515 within the tip 406 of the tetherableguide-sheath 400 may have a chamber volume that is at least as large asa volume occupied by the anchor 102 when the anchor 102 is in theunexpanded, lower profile state. The chamber 515 may also have avariable chamber volume as described in more detail below with respectto FIGS. 17A-17B.

Referring to FIG. 15C, a detailed sectional view, taken from Detail B ofFIG. 15A, of a distal portion of a tetherable guide-sheath isillustrated in accordance with an implementation. In an implementation,the separation between the working lumen 410 and the tether lumen 408proximal to the mouth 508 may have a termination point distal to thetether gripper and/or the exit port of the tetherable guide-sheath 400.For example, the wall 517 dividing the working lumen 410 and the tetherlumen 408, which the ramp 710 makes up a portion of, may end proximal tothe mouth 508. This may allow the anchor 102 to remain separated from aworking device in the working lumen 410 in the distal region of thetetherable guide-sheath 400. However, separation between the tether 104and the working device at a location proximal to the mouth 508 may beless critical, and thus, the separating barrier or wall 517 mayterminate near this region in order to maximize the cross-sectional areaof a proximal portion of the tetherable guide-sheath 400. It will beappreciated that when there is no separating barrier between the workinglumen 410 and the tether lumen 408 the lumens merge into a common lumen409 and the tether 104 and the working device exit through a singleproximal port, e.g., in the tether gripper 1502. Furthermore, it will beappreciated that a proximal edge of the separating barrier 517 mayinclude a tapered wall thickness to ease the distal joint 108 of theworking device as it is advanced from the common lumen 409 into theworking lumen 410 and through the mouth 508.

Referring to FIG. 16A, a sectional view of a tetherable guide-sheath isillustrated in accordance with an implementation. The availablecross-sectional area of the tetherable guide-sheath 400 may be used tomaximize the working lumen 410 and to minimize the tether lumen 408. Forexample, the body 402 of the tetherable guide-sheath 400 may surroundthe working lumen 410 defined by an inner diameter of a working lumenliner 418, and the tether lumen 408 may be defined by an inner diameterof a tether lumen liner 420. The lumen liners 418, 420 may be, forexample, non-concentric tubes that are laterally spaced and positionedadjacent to one another. In an implementation, a dimension of the tetherlumen 408 is large enough to allow a slip fit between the tether lumenliner 420 of the tetherable guide-sheath 400 and the runner tube 113 ofthe tethering device 100. The dimension, however, may not be largeenough to allow a slip fit between the tether lumen liner 420 and thepusher tube 109 of the tethering device 100. More particularly, thetether lumen 408 may be configured to advance over the tether 104 onlyafter the pusher tube 109 has been removed. Accordingly, cross-sectionalarea that would otherwise be required to receive the runner tube 113 mayinstead be dedicated to the working lumen 410, and thus, the workinglumen 410 may be maximized within the available cross-sectional area ofthe tetherable guide-sheath 400.

The inner liners can be constructed from a low friction polymer such asPTFE (polytetrafluoroethylene) or FEP (fluorinated ethylene propylene)to provide a smooth surface for the advancement of devices through theinner lumen. An outer jacket material can provide mechanical integrityto the inner liners and can be constructed from materials such as PEBAX,thermoplastic polyurethane, polyethylene, nylon, or the like. A thirdlayer can be incorporated that can provide reinforcement between theinner liner and the outer jacket. The reinforcement layer can preventflattening or kinking of the inner lumens of the body 402 to allowunimpeded device navigation through bends in the vasculature as well asaspiration or reverse flow. The body 402 can be circumferentiallyreinforced. The reinforcement layer can be made from metal such asstainless steel, Nitinol, Nitinol braid, helical ribbon, helical wire,cut stainless steel, or the like, or stiff polymer such as PEEK. Thereinforcement layer can be a structure such as a coil or braid, ortubing that has been laser-cut or machine-cut so as to be flexible. Inanother implementation, the reinforcement layer can be a cut hypotubesuch as a Nitinol hypotube or cut rigid polymer, or the like. The outerjacket of the body 402 can be formed of increasingly softer materialstowards the distal end. For example, proximal region of the body 402 canbe formed of a material such as Nylon, a region of the body 402 distalto the proximal region of the body 402 can have a hardness of 72 Dwhereas areas more distal can be increasingly more flexible and formedof materials having a hardness of 55 D, 45 D, 35 D extending towards thedistal tip 406, which can be formed of a material having a hardness of35 D, for example. The body 402 can include a hydrophilic coating.

Referring to FIG. 16B, a sectional view of a tetherable guide-sheath isillustrated in accordance with an implementation. Dimensions of thetether lumen 408 and a working lumen 410 of the tetherable guide-sheath400 may be varied in accordance with the principle described above. Moreparticularly, although the size of the tetherable guide-sheath 400 maybe changed to accommodate a particular anatomy and/or intended workingdevice, the tether lumen 408 may be sized to receive the runner tube 113of a corresponding tethering device 100 in the anchoring deliverysystem, but may not be large enough to receive the pusher tube 113 ofthe corresponding tethering device 100.

The flexibility of the body 402 can vary over its length, withincreasing flexibility towards the distal portion of the body 402. Thevariability in flexibility may be achieved in various ways. For example,the outer jacket may change in durometer and/or material at varioussections. A lower durometer outer jacket material can be used in adistal section of the guide-sheath compared to other sections of theguide-sheath. Alternately, the wall thickness of the jacket material maybe reduced, and/or the density of the reinforcement layer may be variedto increase the flexibility. For example, the pitch of the coil or braidmay be stretched out, or the cut pattern in the tubing may be varied tobe more flexible. Alternately, the reinforcement structure or thematerials may change over the length of the elongate body 402. Inanother implementation, there is a transition section between thedistal-most flexible section and the proximal section, with one or moresections of varying flexibilities between the distal-most section andthe remainder of the elongate body 402. In this implementation, thedistal-most section is about 2 cm to about 5 cm, the transition sectionis about 2 cm to about 10 cm and the proximal section takes up theremainder of the sheath length.

FIGS. 17A-17B illustrate an implementation of a distal end of atetherable guide-sheath 400 including a variable volume chamber 515. Asmentioned above, the ramped deflecting surface 710 can deflect workingdevices from the working lumen 410 out through the mouth 508 as theworking device exits the guide-sheath 400. The ramped deflecting surface710 may be formed from a flexible membrane that is able to move, forexample, toward the mouth 508 or toward an interior of the chamber 515.Thus, the ramp 710 may flex toward the chamber when a working device isbeing delivered through the mouth 508 of the working lumen 410.Similarly, after the working device is removed from the working lumen410, the ramp 710 may flex toward the mouth 508 to capture the anchor102 within the chamber 515.

As mentioned, the tetherable guide-sheath 400 may capture the anchor 102of the tethering device 100 in one of the lumens of the tetherableguide-sheath 400. The ramp 710 not only can deflect working devices asthe devices exit the tetherable guide-sheath 400, but also can deflectthe anchor 102 of the tethering device 100 as it is withdrawn into thechamber 515. As an anchor 102 of a tethering device 100 is withdrawn ina proximal direction through the tether distal port 504 into chamber515, the anchor 102 can be deflected from the expanded state towards theunexpanded state as a reaction to a relative lack of expansion of thetether distal port 504 as compared to the anchor 102 of the tetheringdevice 100 (see FIG. 17A) as the anchor 102 is withdrawn into the tetherlumen 408. More particularly, as described below, the distal tip of thetetherable guide-sheath 400 may be advanced over the tether 104 to theanchor 102 of the tethering device 100 in the anchoring vessel, and thedesign of the anchor 102 may allow the anchor 102 to collapse as thedistal tip of the tetherable guide-sheath 400 swallows the anchor 102and the anchor 102 is pulled into the distal tether lumen 708 segment.In some implementations, the tether distal port 504 can have a largediameter at the tip where the anchor 102 is withdrawn to avoidadditional friction. The retrieval of the anchor 102 of tethering device100 may therefore be a smooth interaction having a reduced likelihoodthat the anchor 102 will catch on the distal tip or fracture on an edgeof the distal tip of the tetherable guide-sheath 400. Traction can beapplied to the tether 104 simultaneously as the tetherable guide-sheath400 is advanced forward so that the tethering device 100 causes minimaltrauma to the vessel. Once the tip of the tetherable-guide sheath 400 isadvanced over guide tether 104 and reaching the anchor 102 in the ECA,the design of the tethering device 100 can allow the anchor 102 tocollapse as the distal tip of the guide-sheath 400 swallows the anchor102. In some implementations, the withdrawal of the anchor 102 can causeexpansion of deflecting surface into the working lumen 410. At the endof the procedure, such reduction in working lumen diameter 410 can beacceptable. In some implementations, an outer diameter of the tetherableguide-sheath 400 minimally increases with the capture of the anchor 102of the tethering device 100. For example, the distal region of thetetherable guide-sheath 400 can have an inner diameter of about 0.087″to 0.088″ and can be enlarged to a diameter of about 0.100″ to 0.120″although the size can vary and/or can be flared.

FIGS. 18-20 illustrate different configurations of an anchoring deliverysystem 10 having a tethering device 100 and a tetherable guide-sheath400 configured to receive a working device 802 therethrough. FIG. 18shows a tethering device 100 extending through a tether lumen 408 of atetherable guide-sheath 400 and a working device 802 extending through aworking lumen 410 of the tetherable guide-sheath 400. The anchoringdelivery system 10 may include a combination of the tethering device 100and the tetherable guide-sheath 400. For example, the anchoring deliverysystem 10 may be manufactured as a kit including at least the tetheringdevice 100 and the tetherable guide-sheath 400. The kit can include oneor more tethering devices 100 and one or more tetherable guide-sheaths400, such as a first tetherable guide-sheath 400 having a first innerdiameter and a second tetherable guide-sheath 400 having a second,larger inner diameter. In some implementations, the kit can include thetethering device 100 pre-assembled with one or more of a hypotubepositioned over the tether 104 and the anchor 102 in a low profileconfiguration within a delivery tool. It should be appreciated that thetethering device 100 can be provided separately from the tetherableguide-sheath 400 such that it can be used with another appropriatelysized commercial guiding sheath as described elsewhere herein. Thedifferent inner diameters of the tetherable guide-sheaths 400 can beused to receive different outer diameter working devices 802. In someimplementations, the working lumen 410 of a first tetherableguide-sheath 400 can have an inner diameter that is 6 F and the workinglumen 410 of a second tetherable guide-sheath 400 can have an innerdiameter that is 8 F. The 6 F has an inner diameter of 0.071″ and the 8F has an inner diameter of 0.088″. Thus, the tetherable guide-sheaths400 can receive working devices having an outer diameter that is snug tothese dimensions. It should be appreciated that the tetherableguide-sheath 400 can be OTW or RX, which will be described in moredetail below.

During use, the tethering device 100 may be physically coupled with thetetherable guide-sheath 400, e.g., by tracking the tetherableguide-sheath 400 over the tethering device 100 and/or by locking thecomponents together, as described below. When the tetherableguide-sheath 400 includes a centrally located tether distal port 504distal to the mouth 508, the tether 104 of the tethering device 100 mayextend distally from the tether distal port 504 to the deployed anchor102 along the longitudinal axis passing through the body 402 of thetetherable guide-sheath 400. Furthermore, the anchoring delivery system10 can include a working device 802, which may be packaged as part ofthe same kit or provided separately as its own kit, to be delivered to atarget anatomy. During use, the working device 802 can be trackedthrough the tetherable guide-sheath 400 to exit the tetherableguide-sheath 400 through the mouth 508, the mouth 508 optionally locatedbetween the radiopaque markers 510, into the target anatomy. The targetanatomy can bifurcate away from the anchoring anatomy. It should beappreciated that the anchoring delivery system 10 shown in FIG. 18 caninclude any of a variety of tethering devices described herein includinga tethering device 100 incorporating an anchor 102 configured to take ona higher profile configuration.

Referring to FIG. 19, a distal end of an anchoring delivery systemhaving a tethering device 100 in a tether lumen 408 of a tetherableguide-sheath 400 and a working device 802 in a working lumen 410 of thetetherable guide-sheath 400 is illustrated in accordance with animplementation. The tethering device 100 can include an anchor 102configured to be released from constraint and expanded in the anchoringanatomy at a location distal to the tetherable guide-sheath 400. Moreparticularly, the tether 104 can extend proximally from the deployedanchor 102 through the tether distal port 504 and within the tetherlumen 408 to an exit port in the tetherable guide-sheath 400. Similarly,the working device 802 being delivered to the target anatomy can passthrough the working port 506 and the working lumen 410 to a proximalexit point, e.g., at the proximal furcation 404. As shown, when thetether distal port 504 and the working port 506 are formed in a distalface 502 of the body 402, the tether 104 and the working device 802 canexit the tetherable guide-sheath 400 generally parallel to each other.The components may, however, diverge along different paths. For example,the tether 104 may extend distally into the anchoring anatomy and theworking device 802 may extend distally into the target anatomy, whichmay bifurcate away from the anchoring anatomy. It should be appreciatedthat the anchoring delivery system shown in FIG. 19 can include any of avariety of tethering devices described herein including a tetheringdevice incorporating an anchor configured to take on a higher profileconfiguration.

Referring to FIG. 20, a distal end of an anchoring delivery systemhaving a tethering device 100 and a working device 802 in a same lumenof a tetherable guide-sheath 400 is illustrated in accordance with animplementation. When the tetherable guide-sheath 400 includes a workingport 506 in the distal face 502 of the body 402 and one or more tetherentry ports 504 in the side surface of the body 402, the tetheringdevice 100 may extend laterally through the tether entry ports 504 intothe anchoring anatomy and the working device 802 to be delivered to thetarget anatomy can extend distally from the distal face 502 along alongitudinal axis of the body 402. As described above, depending uponthe tether distal port 504 through which the tether 104 is inserted, adifferent length of the tetherable guide-sheath 400 may be tracked intothe target anatomy. For example, a segment of the tetherableguide-sheath 400 distal to the tether distal port 504 holding the tether104 may be advanced into the target anatomy that bifurcates from theanchoring anatomy. Accordingly, the tether 104 and the segment of thetetherable guide-sheath 400 distal to the utilized tether distal port504 may be pressed against the carina at which the anchoring anatomy andthe target anatomy bifurcate. It should be appreciated that theanchoring delivery system shown in FIG. 20 can include any of a varietyof tethering devices described herein including a tethering deviceincorporating an anchor configured to take on a higher profileconfiguration.

As shown in FIG. 20, tetherable guide-sheath 400 can include a singlelumen in which at least one elongated structure can be received. Forexample, the tether lumen 408 and the working lumen 410 can be a samelumen running longitudinally through tetherable guide-sheath 400 fromproximal furcation 404 to tether distal port 504 and working port 506.Thus, the tether 104 may enter a same lumen of tetherable guide-sheath400 through the tether distal port 504 as the working device 802 entersthrough the working port 506, rather than being received by separatelumens of tetherable guide-sheath 400. Thus, working port 506 shown inFIG. 20 can also be the tether distal port 504.

According to some implementations, the length of the tetherableguide-sheath 400 is long enough to access the target anatomy and exitthe arterial access site with extra length outside of a patient's bodyfor adjustments. For example, the tetherable guide-sheath 400 can belong enough to access the petrous ICA from the femoral artery such thatan extra length is still available for adjustment. The tetherableguide-sheath 400 can be a variety of sizes to accept various workingdevices 802 and can be accommodated to the operator's preference. Forexample, current MAT and SMAT techniques describe delivering aspirationcatheters having inside diameters of 0.071-0.072 inches to an embolusduring AIS. Accordingly, the working lumen 410 of the tetherableguide-sheath 400 can be configured to receive such aspiration cathetersas the working device 802. It should be appreciated that theguide-sheaths described herein can be sized to receive other types ofworking devices besides aspiration catheters, such as stent deliverycatheters. For example, the working lumen 410 can have an inner diameterof at least 6 French, or preferably at least 6.3 French to accommodatesuch working devices 802. The inner diameter of the tetherableguide-sheath 400, however, may be smaller or larger. In someimplementations, the working lumen 410 can have an inner diameter of 7French or 8 French to accommodate even larger working devices 802. Insome implementations, the working lumen 410 can having inner diameter of0.088″ or 0.071″ and thus, are configured to receive a working device802 having an outer diameter that fits snug with these dimensions.Regardless of the length and inner diameter, the tetherable guide-sheath400 is resistant to kinking during distal advancement through thevasculature.

Referring to FIG. 21, a perspective view of a tetherable guide-sheath isillustrated in accordance with an implementation. The tetherableguide-sheath 400 can be a rapid exchange (RX) type device. Accordingly,the tetherable guide-sheath 400 can include a hypotube 1102 extendingdistally from a connector 1104 at a proximal end 403. The hypotube 1102can be coupled with the body 402 of the tetherable guide-sheath 400 at ajoint between the connector 1104 and the tip 406. Furthermore, an exitport 1106 can be positioned distal from the joint. The exit port 1106can connect with the tether lumen 408 in the body 402. Furthermore, theconnector 1104 can connect with the working lumen 410 in the body 402.

Referring to FIG. 22, a sectional view, taken about line B-B of FIG. 20,of a tetherable guide-sheath is illustrated in accordance with animplementation. The body 402 of the tetherable guide-sheath 400 caninclude one or more lumens extending longitudinally toward the tip 406.For example, the body 402 can include the tether lumen 408 to receivethe tether 104 of the tethering device 100. Furthermore, the body 402can include the working lumen 410 to receive the working device 802 tobe delivered through tetherable guide-sheath 400 to a target anatomy.The lumens 408, 410 can be sized to receive their respective workingdevices in a sliding fit. For example, the tether 104 can have an outerdiameter of 0.014 inch and the tether lumen 408 can have an innerdiameter in a range of 0.015-0.020 inch sufficient to receive the outerdiameter of the tether 104. Similarly, the tether 104 can have an outerdiameter of 0.035 inch and the tether lumen 408 can have an innerdiameter in a range of 0.036-0.041 inch. The working lumen 410 may besimilarly sized according to the working device 802 that will bedelivered through it to the target anatomy.

Referring to FIG. 23, a sectional view, taken about line C-C of FIG. 20,of a tetherable guide-sheath is illustrated in accordance with animplementation. When tetherable guide-sheath 400 is an RX-type workingdevice, the hypotube 1102 may have an inner diameter that is at least aslarge as the working lumen 410 in the body 402. For example, the workinglumen 410 in the hypotube 1102 may have a diameter that is at least0.001 inch larger than any working device 802 that it is intended toreceive.

Referring to FIG. 24, a sectional view of a proximal end of the tetherlumen of a tetherable guide-sheath is illustrated in accordance with animplementation. When the tetherable guide-sheath 400 is an RX typedevice, the tether 104 of the tethering device 100 can exit the exitport 1106 in the body 402 distal to the hypotube 1102, which containsthe working lumen 410 of the tetherable guide-sheath 400. Accordingly,the exit port 1106 may be considered to be the proximal furcation 404 inthe tetherable guide-sheath 400, as it represents a location where thetether 104 and the working device 802 diverge from each other at aproximal location in the system. In practice, the exit port 1106 can belocated within the patient, and thus, the tether 104 and the hypotube1102 can emerge from the access site in a side-by-side manner. Thetether lumen 408 and the working lumen 410 can extend along respectivelongitudinal axes that are parallel to each other near the exit port1106. However, like the mouth 508 of the tetherable guide-sheath 400,the tether lumen 408 may be directed toward the exit port 1106 formed inthe side surface of the body 402 such that the tether 104 exits the body402 at an angle to the longitudinal axis of the tether lumen 408. Thisexit angle may be controlled by a radius used to form the exit port1106.

As mentioned above, the anchoring delivery systems described herein caninclude a tether gripper 1502 to fasten the tether 104 of the tetheringdevice 100 to the tetherable guide-sheath 400. FIG. 25 shows a tethergripper 1502 in accordance with an implementation. More particularly,one or more of the tethering device 100 or the tetherable guide-sheath400 can include the tether gripper 1502 at a point of fixation betweenthe components to attach the tetherable guide-sheath 400 to the tether104 of the tethering device 100. Thus, the tetherable guide-sheath 400can be reversibly attachable to the tether 104 at the point of fixation,which can be located proximal to the anchoring site at which the anchor102 of the tethering device 100 is deployed within the anchoringanatomy. Accordingly, when the anchor 102 is deployed at the anchoringsite and the tetherable guide-sheath 400 is attached to the tether 104at the point of fixation, any proximal loading applied to the tetherableguide-sheath 400 distal to the fixation point can tension the tether 104between the anchoring site and the point of fixation. Furthermore, thistension can have a straightening effect on the tetherable guide-sheath400 to increase the column strength of the tetherable guide-sheath 400and buttress the tetherable guide-sheath 400 against buckling orprolapse. Proximal loading on the tetherable guide-sheath 400 may resultfrom, e.g., delivery or advancement of the working device 802 throughthe working lumen 410 of the tetherable guide-sheath 400 toward thetarget anatomy. Thus, the support provided by fixing the tether 104 tothe tetherable guide-sheath 400 in combination with anchoring within theanatomy by the anchor 102 can prevent buckling of the tetherableguide-sheath 400 during working device 802 delivery, which can improvethe ease and success of any interventional procedure performed throughthe tetherable guide-sheath 300.

In an implementation, the tether gripper 1502 is incorporated in thetetherable guide-sheath 400. One or both of the tether proximal port 414or the working proximal port 416 can incorporate a tether gripper 1502.The tether gripper 1502 can include a clamping or clipping mechanism,such as a cleat, clamp, clip, etc., to fix the respective proximal portto a separate device passing through the port. The tether gripper 1502can also include tape or suture to fix the respective proximal port to aseparate device passing through the port. By way of example, the tetherproximal port 414 can include an RHV capable of being tightened onto therunner tube 113 of the tethering device 100 when the runner tube 113extends through the tether lumen 408 of the tetherable guide-sheath 400.As such, a fixation point may be formed between the tethering device 100and the tetherable guide-sheath 400 at the tether gripper 1502 at somepoint proximal to the tether distal port 504. Again with respect to FIG.25, the tether gripper 1502 can include a fixation mechanism having agripper body 1504 that includes the tether lumen 408 and a cap 1506 thatscrews onto the gripper body 1504 via fastening threads 1508.Furthermore, the tether gripper 1502 can include one or more seals 1510that surround the tether 104 when it is passed through the gripper body1504, and thus, prevents fluid leakage through the tether gripper 1502.It will be appreciated that the seal 1510 is illustrated here without abacking surface, but in an implementation, the tether gripper 1502 canbe designed such that the seal 1510 is squeezed when the cap 1506 isscrewed onto the gripper body 1504. The seal 1510 can squeeze the tether104 with enough force to fasten the tether 104 within the tether gripper1502. In an implementation, the tether gripper 1502 can include arotating hemostatic valve (RHV) that is configured to fix the tether 104to the tetherable guide-sheath 400 without additional clamping features.For example, the RHV can be connected to the proximal furcation 404 andcan be actuated to compress the seal 1510 that grips the tether 104.

In an implementation, the tether gripper 1502 can incorporate additionalclamping features to grip the tether 104. For example, a collet 1512component can be incorporated in the tether gripper 1502 such that thetether 104 passes through a central opening of the collet 1512 betweenthe collet 1512 teeth. When the cap 1506 is screwed onto the gripperbody 1504, a taper 1514 in the cap 1506 can press against the collet1512 teeth forcing them against the tether 104. Accordingly, the tether104 can be gripped with greater force than can be achieved using, e.g.,an elastomeric seal 1510, and the tether gripper 1502 of the tetherableguide-sheath 400 can be used to fix the tetherable guide-sheath 400 tothe tether 104.

FIG. 26 shows a further implementation of a tether gripper of atetherable guide-sheath. The tether gripper 1502 of the tetherableguide-sheath 400 can be incorporated in the proximal furcation 404 ofthe tetherable guide-sheath 400. For example, the proximal furcation 404can include a gripping feature to clamp the tether 104. For example, thetether gripper 1502 can include a slot 1516 formed through a sidewall ofthe proximal furcation 404 such that the tether 104 can be pulledlaterally outward through the proximal furcation 404. Furthermore, bypulling the tether 104 out and upward through the slot 1516 withsufficient force, the tether 104 can be wedged toward a distal portionof the slot 1516. Accordingly, the tether gripper 1502 can pinch thetether 104 and prevent movement between the tether 104 and the tethergripper 1502. More particularly, the tether gripper 1502 can fix thetether 104 to the tetherable guide-sheath 400.

In the tether gripper 1502 implementations described above with respectto FIGS. 25-26, the tether lumen 408 may extend from the tether distalport 504 at the tip 406 of the tetherable guide-sheath 400 to the tethergripper 1502 connected to or incorporated in the tetherable guide-sheath400.

As described above, the tetherable guide-sheath 400 can also be an RXtype device such that the tether 104 can exit the tetherableguide-sheath 400 through the exit port 1106 within the patient anatomyas shown in FIG. 21. Thus, the exit port 1106 may not be reachable tofix the tether 104 to the tetherable guide-sheath 400 at the exit port1106. FIG. 27 shows an implementation of a tether gripper 1502 of atethering device 100 for use with an RX type guide-sheath. The tether104 can be attached to the tetherable guide-sheath 400 proximal to theexit port 1106, e.g., using a clamp, clip, etc., to fasten the tether104 to the body 402 of the tetherable guide-sheath 400. The distancebetween the fixation point and the exit port 1106 in such a case,however, may allow the tether 104 to bend relative to the tetherableguide-sheath 400 such that the tetherable guide-sheath 400 is notadequately buttressed against buckling. Accordingly, the tether gripper1502 can be incorporated in the tether 104 to fix the tether 104 to thetetherable guide-sheath 400 within the tether lumen 408. For example,the tether gripper 1502 can be integrated in the tether 104 at alocation distal to the exit port 1106. In an implementation, the tethergripper 1502 can include an expandable structure 1518 that can expandradially within the tether lumen 408 to press against an inner surfaceof the tether lumen 408 and lock the tether 104 to the tetherableguide-sheath 400 from moving slideably within the lumen 408. Theexpandable structure 1518 can be a self-expanding structure that iscaptured by a thin tubular sheath disposed over a proximal segment ofthe tether 104. More particularly, the thin tubular sheath can beretracted to expose the expandable structure 1518 and allow it to expandagainst the tether lumen 408 surface to lock the tether 104 to thetetherable guide-sheath 400. Furthermore, the thin tubular sheath can beadvanced to capture the expandable structure 1518 and allow thetetherable guide-sheath 400 to be tracked over the tether 104 again.

The expandable structure 1518 of the tether gripper 1502 can be aninflatable member, such as a balloon, that is not self-expandableso-to-speak. More particularly, the tether 104 can have a tubularstructure along a proximal segment. The tubular structure can have aproximal end 106 in fluid communication with the tether gripper 1502.The tether gripper 1502 can be connected to a syringe for inserting aninflation fluid into the tubular structure. Thus, the inflation fluidcan be delivered into an inner volume of the expandable structure 1518located at a distal joint of the tubular structure, causing the balloonto be inflated to press against the tether lumen 408 surface. Thetubular structure can have a distal joint connected with a proximal endof a core wire. More particularly, the tether 104 can include a distalsegment having a core wire extending from the distal joint of thetubular structure to the anchor 102. Accordingly, the tethering device100 can include an anchor 102 at a distal joint 108, a core wire portionof the tether 104 extending proximally from the anchor 102, and a tethergripper 1502 portion extending proximally from the core wire portion.The tether gripper 1502 implementations described above are not intendedto be limiting, but rather, illustrate that the tether gripper 1502 canbe incorporated in one or both of the tethering device 100 or thetetherable guide-sheath 400 to fix the components of the anchoringdelivery system 10 to each other during use.

Methods of Using an Anchoring Delivery System to Deploy a Working Device

As described above, advancement of a working tool such as a stentdelivery system over a guidewire through an access sheath can createback and forth motion exacerbated by a laxity present in typical sheathsystems. Upon meeting resistance, the stent delivery system can createtension that forces the entire delivery system downward (e.g. into theaorta) and laterally (e.g. against the vessel wall). Depending on thesize of the vessel, there may be a greater or lesser effect than theprolapse or buckling into the aorta. The anchoring delivery systemsdescribed herein can address many of the issues that standardneurovascular delivery systems can create.

Referring to FIG. 28, a method of using an anchoring delivery system todeliver a working device that is an implant delivery system isillustrated in accordance with an implementation. FIGS. 29A-29Fillustrate operations of the method illustrated in FIG. 28. Accordingly,FIGS. 28-29 are described in combination below. It should be appreciatedthat the implant delivery system can vary and includes a standardneurovascular delivery system having a flow diverter or a stent implant.

An arterial access device 1902, such as a standard transfemoral sheath,can be inserted into an arterial access point such as the femoralartery. Referring to FIG. 29A, the arterial access device 1902 is showninserted via a percutaneous puncture into the common femoral artery(CFA), such as near the groin. In alternate implementations, otheraccess points can be used such as radial artery access, brachial arteryaccess, transcervical or transcarotid access to the CCA or proximalinternal carotid artery (ICA), or any other access point. In someimplementations, arterial access device 1902 has an inside diameterrange of 3 to 10 French. For example, the transfemoral sheathillustrated in FIG. 21A can be a standard 7 French sheath size.

After inserting the arterial access device 1902, a finder tool set,which can include a guidewire (not shown), a microcatheter 1910, and/ora finder catheter 1908, can be inserted individually or in combinationinto the transfemoral sheath and advanced to an anchoring vessel 1904,e.g., an ECA, ICA, CCA, etc. For example, a guidewire can be advanced tothe distal ECA, ipsilateral to a target vessel 1906, which may be theICA, using conventional techniques known to persons having ordinaryskill in the art. For example, the guidewire can be preloaded into afinder catheter 1908 and advanced to the aortic arch (AA). In someimplementations, the finder catheter 1908 includes a hook-shaped distalsection, such as in the case of a Vertebral, Hockey Stick, VTK shape, orLIMA pre-shaped catheter or the like. A distal end of the findercatheter 1908 can be manipulated and positioned at the brachiocephalicartery or right CCA. The guidewire can then be pushed up as far aspossible to the anchoring vessel 1904, e.g., the distal ipsilateral ECA.A microcatheter 1910 can be advanced over the guidewire. Optionally, thefinder catheter 1908 can be advanced over the guidewire and themicrocatheter 1910 to an anchoring site of the anchoring vessel 1904,e.g., the ECA distal to a takeoff of the target vessel 1906.

At operation 1802, the tethering device 100 can be delivered to theanchoring vessel 1904. For example, still referring to FIG. 29A, theguidewire can be removed from the microcatheter 1910 and the tetheringdevice 100 can be inserted into and advanced through a lumen of themicrocatheter 1910 and the finder catheter 1908 until the anchor 102 isnear the anchoring vessel 1904. As described above, the tethering device100 can include an anchor 102, such as an expandable element that cananchor and/or fix into an artery with or without scaffolding the artery,and the anchor 102 can be connected to the tether 104, which includes anelongated member. The anchor 102 is not shown in FIG. 29A, since it ishidden within a distal region of the microcatheter 1910 placed in theanchoring vessel 1904. Thus, delivery of the tethering device 100 to theanchoring vessel 1904 can include advancement of the anchor 102connected to the distal end of the tether 104 through the vasculature,and not necessarily deployment of the anchor 102 from the unexpandedstate to the expanded state. Depending on the implementation, thetethering device 100 can include a pusher tube, such as a hypotube,extending over the tether 104 such that a distal end of the pusher tubeis positioned adjacent a proximal end of the anchor 102, such as ananchor shown in FIGS. 5H-5K. The pusher tube can provide “pushability”to an otherwise floppy tether 104 such that the anchor 102 can beadvanced through the microcatheter 1910 positioned within the vessel. Adistal end of the pusher tube 109 can abut against the anchor 102 andurge it forward through a lumen of the microcatheter 1910. The tetheringdevice 100 and the pusher tube 109 can be preloaded or otherwiseassembled with a delivery tool configured to maintain the anchor 102 ina low profile configuration such that the anchor 102 can be insertedinto a proximal end of the microcatheter 1910 and advanced to the distalanchoring vessel 1904 through the microcatheter 1910 lumen.

At operation 1804, the anchor 102 of the tethering device 100 can bedeployed in the anchoring vessel 1904. Referring to FIG. 29B, themicrocatheter 1910 can be retracted over the tethering device 100 tounsleeve and expose the anchor 102 of the tethering device 100. In thecase of a self-expanding anchor 102 structure (see, e.g., FIG. 2B or5J), the anchor 102 of the tethering device 100 can automatically deployinto the anchoring vessel 1904. Alternatively, in the case of aninflatable anchor 102 structure (see, e.g., FIG. 2C), the anchor 102 canbe manipulated to deploy into the anchoring vessel 1904. Moreparticularly, the anchor 102 can transition from the low profile,unexpanded state to the higher profile, expanded state to contact andanchor 102 at an anchoring site within the anchoring vessel 1904, e.g.,distal to an entrance of the target vessel 1906.

Referring to FIG. 29C, the microcatheter 1910 and/or the finder catheter1908 can be removed through the arterial access device 1902 such thatthe tethering device 100 is anchored within the anchoring vessel 1904and a proximal end of the tether 104 extends from the distal joint 108through the arterial access device 1902. In some implementations,deployment of the anchor 102 and/or the deployed anchor 102 of thetethering device 100, e.g., expansion of a cage structure or inflationof a balloon anchor, or release of a wire device, may cause endothelialinjury. Accordingly, application of tension to the tether 104 when theanchor 102 is deployed may create shear stress on the vascular tissueand/or distortion of the vascular anatomy at a location of the anchordeployment. However, minor vascular trauma in the anchoring vessel 1904may be an acceptable tradeoff to get a supportive system in place whenan aneurysm at risk for rupture or a stroke-inducing embolism orstenosis is the clinical indication for the target vessel 1906. It isalso comprehended that the anchoring delivery system presented hereinmay also be used where the clinical syndrome is severe and the “cost” oftrauma at an endothelial cell layer level in the anchoring vessel 1904is acceptable in the judgment of the operator to achieve a desiredoutcome in the target vessel 1906. The anchoring delivery system mayalso be used for cases with or without aneurysm or stenosis whereintracerebral access is needed, as compared to current transfemoralsystems that simply do not allow such access.

At operation 1806, the tetherable guide-sheath 400 may be advanced overthe tether 104 of the tethering device 100 to position the mouth 508 ofthe tetherable guide-sheath 400 near the entrance of the target vessel1906. The tether 104 can include a length extending outside the patient.Referring to FIG. 29D, the proximal end 106 of the tether 104 (extendingoutside the patient) can be inserted into the tether distal port 504 ofthe tetherable guide-sheath 400 at a distal end of the tether lumen 408.Thus, the tether 104 can be received in the tether lumen 408. The lengthof the tether 104 extending outside the patient can be advanced throughthe tether lumen 408 until the proximal end of the tether 104 is onceagain available outside the proximal end of the sheath 400, for exampleby extending from the tether lumen 408 through the tether proximal port414. Although the tether 104 is generally not pushable up through thevasculature without a pusher tube or some kind of delivery component,the tether 104 can have enough heft that it can be pushed through thetether lumen 408 of the sheath 400. Once the tether 104 extends out thetether proximal port of the sheath 400, the tetherable guide-sheath 400can be advanced into the patient over the tether 104. The tetheringdevice 100 between the anchor 102 and the proximal end of the tether 104can be made taut such that the tether 104 of the tethering device 100can function like a rail for advancing the tetherable guide-sheath 400up the tether 104 until the working port 506, e.g., the mouth 508, ofthe tetherable guide-sheath 400 is positioned at the entrance to thetarget vessel 1906. The entrance to the target vessel 1906 can be, forexample, a carotid bifurcation, and thus, the mouth 508 may provideaccess to the ICA. Thus, the tetherable guide-sheath 400 can bepositioned to deliver a working device 802 toward the target vessel 1906through the working lumen 410 in the proximal furcation 404 while thetether 104 of the tethering device 100 exits the tetherable guide-sheath400 through the tether lumen 408 in the proximal furcation 404.

The tether 104 can provide the route for the tetherable guide-sheath400, and the tether 104 can extend the length of the vascular path andexit near a distal end of the tetherable guide-sheath 400, e.g., throughthe tip 406 or a side of the tetherable guide-sheath 400 near the tip406, leaving the working lumen 410 of the tetherable guide-sheath 400available for petrous access. The length of the tether 104 can varydepending on the type of the tetherable guide-sheath 400. Moreparticularly, the tetherable guide-sheath 400 can be an over-the-wire(OTW) type device, having an exit port at a proximal end, or a rapidexchange (RX) type device, having the exit port 1106 at a mediallocation between ends. Thus, in the case of an OTW tetherableguide-sheath 400, the tether 104 runs within the tether lumen 408extending the length of the tetherable guide-sheath 400. Alternatively,in the case of the RX tetherable guide-sheath 400, the tether 104 runswithin the tether lumen 408 extending from the tip 406 of the tetherableguide-sheath 400 to an exit port 1106 where the tether lumen 408terminates on the outside of the tetherable guide-sheath 400. Since thelength of the tether lumen 408, which receive the tether 104, can beshorter in an RX type than in an OTW type of tetherable guide-sheath400, the length of the tether 104 of the anchoring delivery system mayvary. In some implementations, an extension member having an elongatedbody and a distal end configured to couple with a proximal end 106 ofthe tether 104 can be attached and detached from the tether 104 to allowfor the exchange of one type of tetherable guide-sheath 400, e.g., an RXtype, for another type of tetherable guide-sheath 400, e.g., an OTWtype, while maintaining the position of the tethering device 100 in thetarget anatomy.

Advancing the tetherable guide-sheath 400 over the tether 104 of thetethering device 100 can advance the tip 406 of the tetherableguide-sheath 400 through the entrance of the target vessel 1906 into thetarget vessel 1906. The tetherable guide-sheath 400 can have a stumptip. More particularly, the working port 506 can be distal to one ormore tether entry ports 504 (see, e.g., FIGS. 12A and 13). The tether104 of the tethering device 100 can be inserted through a tether distalport 504 on the side of the tetherable guide-sheath 400 proximal to thetip 406. For example, the tether 104 can be inserted into a tetherdistal port 504 near the tip 406 such that the portion of tetherableguide-sheath 400 distal to the utilized tether distal port 504 is shortenough to be able to be advanced up the tether 104 of tethering device100 through the arteries as well as long enough such that thekeel-shaped intersection of the tetherable guide-sheath 400 and thetether 104 of the tethering device 100 exerts enough force to fix thetetherable guide-sheath 400 against the carina of the anchoringvessel/target vessel bifurcation.

In another implementation, the tether 104 of the tethering device 100 isinserted into the tether distal port 504 spaced further proximally awayfrom the working port 506 at the tip 406. Thus, a longer portion of thetetherable guide-sheath 400 can extend into the target vessel 1906. Thelength of the long tip can vary depending on which tether distal port504 the tether 104 of tethering device 100 is inserted into. That is,when the tether 104 is inserted into a more proximal tether distal port504, then the distance between the utilized tether distal port 504 andthe tip 406 of the tetherable guide-sheath 400 may be longer. In variousimplementations, the at least one tether distal port 504 is adjacent toone or more radiopaque markers 510 (e.g., a pair of radiopaque markers510 may flank the utilized tether distal port 504) to indicate thelocation of the tether distal port 504 under fluoroscopy.

At operation 1808, the tetherable guide-sheath 400 can be attached tothe tether 104 of the tethering device 100. Referring to FIG. 29E, thetether 104 can be fixed to the tetherable guide-sheath 400 at a point offixation 1912 proximal to the entrance of the target vessel 1906. Thetether 104 and the tetherable guide-sheath 400 can be fixed or lockedinto position relative to each other after the tetherable guide-sheath400 is positioned at a carotid bifurcation with the mouth 508 providingaccess to the ICA, creating a tension in the tether 104 between theanchor 102 anchored in the target vessel 1904 distal to the targetvessel 1906 takeoff and the tetherable guide-sheath 400 near thearterial access site. The tether 104 can be affixed to an outer surfaceor an inner surface of the tetherable guide-sheath 400 at the point offixation 1912. The point of fixation 1912 can be outside of the patientanatomy, or in an implementation, the point of fixation 1912 can bewithin the patient anatomy, as may be the case when the tetherableguide-sheath 400 is an RX type device and the tether gripper 1502 isincorporated along the tethering device 100 (FIG. 19). The connectionbetween the tetherable guide-sheath 400 and the tether 104 can beachieved using any of the fixation mechanisms described above, e.g., bythe tether grippers 1502 described with respect to FIGS. 25-27. Suchimplementations, however, are illustrative and not limiting. Forexample, the tether 104 of the tethering device 100 can be attached tothe tetherable guide-sheath 400 using conventional securement techniquessuch as by clamping, taping, or otherwise securing the tether 104 to thetetherable guide-sheath 400.

In an implementation, the tether 104 and the tetherable guide-sheath 400are fixed by a clamp. For example, the clamp can be secured to a tab onthe outside of the tetherable guide-sheath 400 or by other means offixation. In alternative implementations, the tether 104 and thetetherable guide-sheath 400 are fixed by a hemostat, mosquito, suture,by application of a clear dressing or tape (e.g., Tegaderm™ or Opsite™),by a wire grasping element, by a closed RHV, or similar means offixation. In additional various implementations, a non-clamping fixationtechnology can be used to avoid kink development of a mechanicalfixation. For example, the tether 104 and the tetherable guide-sheath400 can be fixed magnetically as described elsewhere herein. Inaddition, the tether 104 can be fixed within a lumen of tetherableguide-sheath 400 closer to the distal tip of tetherable guide-sheath 400using a small interlocking detent within the tetherable guide-sheath400. In an implementation, the tether gripper 1502 includes a balloonthat is inflated within the tetherable guide-sheath 400 to pin thetether 104 within the tether lumen 408 and lock the relationship of thetether 104 to the tetherable guide-sheath 400. In some implementations,the tether 104 can be designed with at least one protrusion, e.g., abulge formed around the tether 104, that engages with the tether lumen408 of the tetherable guide-sheath 400. The bulge can be configured toengage the tether lumen 408 when stationary and can deflate when pushedforward. In an implementation, the tether 104 will not stretch, or mayonly minimally stretch, when pulled on.

At operation 1810, a working device 802 can be advanced through aworking lumen 410 of the tetherable guide-sheath 400 toward the targetanatomy. As described elsewhere herein, the working devices deliveredthrough the guide sheaths described herein can vary and are not intendedto be limiting. For example, the working device 802 can include aguidewire, balloon, advanced catheter, stent, flow diverter, coil, etc.as well as delivery devices configured to deliver stents, flowdiverters, coils, etc. After the tetherable guide-sheath 400 isdelivered to the anchoring vessel/target vessel junction, e.g., theECA/ICA bifurcation, angiography can be performed through the tetherableguide-sheath 400 to allow full opacification of the cerebralvasculature. Referring to FIG. 29F, the operator can then deliver theworking device 802 into the entrance of the target vessel 1906 andproceed with a preferred approach to the treatment site aided by theanchoring provided by the fixed tethering device 100 and tetherableguide-sheath 400, i.e., the anchoring delivery system. The supportprovided by the anchoring delivery system 10 can allow some approachesto be performed when they otherwise could not have been possible becauseof tortuous anatomy either at the great vessels and/or at theintracranial vasculature that tend to result in kinking and prolapse oftypical sheaths as the working device is advanced distally. Moreover,the additional guide support can allow procedures to be completed morequickly, consistently and simply than routine interventional approachesand with greater precision and accuracy.

For example, using an approach to treat a target site that is ananeurysm or stenosis at the M1 segment (one in a main stem of middlecerebral artery), the working device 802 can be an implant deliverysystem delivered through the working lumen 410 of the tetherableguide-sheath 400 to a target site 1914 in the target vessel 1906.Delivery can be facilitated by the anchoring of the tethering device 100and tethering of the tetherable guide-sheath 400, which tensions thetether 104 between the anchoring site and the point of fixation 1912 asthe working device 802 advances through the mouth 508 into the distaltarget vessel 1906. Accordingly, commercially available 6 Frenchintracranial catheter families which have up to 0.072 inch innerdiameters for maximum diameter and stent delivery capability would becompatible with a 7 or 8 French tetherable guide-sheath 400.

In various implementations, once the working device 802, e.g., a stentdelivery system, exits the mouth 508 of tetherable guide-sheath 400 andis in the ICA, the fixation of the tether 104 to the tetherableguide-sheath 400 can be relaxed. The carina formed between the workingdevice 802 and the tetherable guide-sheath 400 can be advanced againstthe carina of the anchoring vessel/target vessel junction, e.g., thecarotid bifurcation, to provide an additional point of securement at thebifurcation. This carina-to-carina cinching between the device junctionand the anatomical junction can reestablish the fixation of thetethering device 100 and the tetherable guide-sheath 400, eliminatingthe possibility of both upward motion of the system and downwardbuckling or prolapsing of the tetherable guide-sheath 400 within the CCAor brachiocephalic artery. If a subsequent device, e.g., a balloonangioplasty device or another tethering device 100, is advanced out ofthe working device 802, a reaction force can be created when that devicemeets resistance. The reaction force can act on the working device 802and may press against the tetherable guide-sheath 400. In the presentsystem, however, the force should not reach the area of the aortic archwhere prolapse is typical in standard systems because of the anchoringof the tethering device 100 and the fixation of the tether 104 to thetetherable guide-sheath 400 as well as the carina-to-carina cinching.The opposite reaction force can be counteracted. For example, when astent delivery catheter is actuated to deploy the stent at the targetlocation the pull can cause the tetherable guide-sheath 400 to rideupward in the vessel. The carina-to-carina cinching can prevent thisupward motion. In essence, the tetherable guide-sheath 400 is lockedinto its relative position in the vasculature and provides a fulcrum foradvancing subsequent devices, e.g., catheter systems and interventionaldevices, into the distal vessels of the neurovasculature.

In an implementation, after the target site 1914 has been successfullytreated, e.g., by installing a stent, flow diverter, or stent-assistedcoil, all wires, retrievable structures, and catheters can be removedfrom the tetherable guide-sheath 400, leaving the anchoring deliverysystem (the tethering device 100 and the tetherable guide-sheath 400).The fixation between the tethering device 100 and the tetherableguide-sheath 400 can be removed. For example, the tether 104 can bedisengaged from the tether gripper 1502. Thus, the tetherableguide-sheath 400 can be advanced over the tether 104 to the anchor 102deployed in the anchoring vessel 1904, e.g., the ECA. In someimplementations, traction on the tether 104 can be applied to keep thetethering device 100 in position and to minimize trauma to the anchoringvessel as the tetherable guide-sheath 400 is advanced. The tetherableguide-sheath 400 can be advanced over the tether 104 to capture theanchor 102. That is, the tetherable guide-sheath 400 can be advanced tocapture the anchor 102 within the tether lumen 408. Accordingly, theanchor 102 can be collapsed towards its lower profile configuration andthe anchor 102 can be disengaged from the anchoring vessel 1904. Theanchoring delivery system can then be retracted from the patient anatomythrough the arterial access by removing tetherable guide-sheath 400 andthe captured anchor 102 from the target anatomy. In an implementation,the tetherable guide-sheath 400 can be removed from the patient, leavingthe deployed tethering device 100 in place, and a separate catheter,e.g., a microcatheter, can be advanced over the tether 104 to capturethe anchor 102 and retrieve the tethering device 100 from the patient.

The method described with respect to FIG. 28 is illustrative, and oneskilled in the art may extrapolate from this description other methodsof using the anchoring delivery system to effectively deliver workingdevice(s) to distal regions of tortuous and complex anatomies. Severalsuch methods are described in the implementations below.

Referring to FIG. 31A, preparation of a patient may be similar to thatdescribed above. For example, an arterial access device 1902, such as astandard transfemoral sheath, can be inserted into an arterial accesspoint such as the femoral artery. At operation 2002, a guidewire 2102can be delivered through the arterial access device 1902 to theanchoring vessel 1904. Subsequently, at operation 2004, a catheter 2103,such as a microcatheter 1910 or a finder catheter 1908, can be deliveredover the guidewire 2102 into an anchoring vessel 1904 of a targetanatomy. In an implementation, the catheter 2103 can be preloaded withthe guidewire 2102, and thus, the guidewire 2102 and the catheter 2103can be advanced simultaneously. The guidewire 2102 can extend at leastthe length of the catheter 2103 and can be independently maneuverablewithin the catheter 2103 to lead the guidewire/catheter system to theanchoring vessel 1904. The coaxial system can be moved as a unit andeach part can be manipulated independently depending on anatomicalrequirements and operator preferences. In particular implementations, afinder catheter 1908 (not shown in this figure) can also be positionedas part of the guidewire/catheter system. Thus, a route for thetethering device 100 can be established by the guidewire 2102 and one ormore catheters 2103.

Referring to FIG. 31B, at operation 2006, the guidewire 2102 isexchanged for the tethering device 100. The guidewire 2102 can beremoved from a lumen of the catheter 2103 and the tethering device 100can be inserted into the catheter 2103 outside of the body 402 using aninsertion tool. Insertion tools are known, for example, to insert aretrievable structure into a patient anatomy during a SMAT procedure, astent during a balloon angioplasty procedure, or to insert a flowdiverter or stent for stent-assisting coils to treat an aneurysm orstenosis. It is also possible that the tethering device 100 is alreadypreloaded in the catheter system and the entire catheter 2103 with thetethering device 100 is inserted into the catheter 2103 instead ofloading the tethering device 100 into the catheter 2103 without an outersheath.

At operation 2008, the anchor 102 of the tethering device 100 can bedeployed in the anchoring vessel 1904, e.g., the ECA. That is, theanchor 102 can be deployed at an anchoring site in the anchoring vessel1904 distal to the entrance of the target vessel 1906. Deployment of theanchor 102 can include a standard “pin and pull” technique to keep theanchor 102 in a fixed position and prevent jumping of the device whilethe catheter 2103 is pulled back to unsleeve the anchor 102.

Referring to FIG. 31C, at operation 2010, the tetherable guide-sheath400 is advanced over the catheter 2103 to position the mouth 508 of thetetherable guide-sheath 400 near an entrance of a target vessel 1906.That is, the tetherable guide-sheath 400 may include a tether lumen 408to receive both the catheter 2103 and the tether 104 to allow thetetherable guide-sheath 400 to be tracked over an outside of thecatheter 2103. Using the tethering device 100 and the catheter 2103 assupport, the tetherable guide-sheath 400 can be advanced into the CCA upto the ECA/ICA bifurcation. Advancement of the tetherable guide-sheath400 leverages the support of the tandem tether 104 and catheter 2103combination, as well as the pulling force that the anchor 102 of thetethering device 100 provides when fully deployed in the ECA. Thetetherable guide-sheath 400 can be advanced to the ECA/ICA bifurcationand a mouth 508 of the tetherable guide-sheath 400 may be directedtowards the targeted vessel 1906, e.g., the ICA. The combination of thecatheter 2103 and the tether 104 may provide sufficient column strengthto reduce the likelihood of prolapse of the tetherable guide-sheath 400into the ascending aorta, and to direct the tetherable guide-sheath 400into the brachiocephalic as described in more detail above.

Referring to FIG. 31D, at operation 2012, the catheter 2103 can beremoved from the tetherable guide-sheath 400. The tether 104 of thetethering device 100 can allow the catheter 2103 to be removed bypulling the catheter 2103 proximally. This differs from other techniquesthat require long wires and long wire exchanges. After the catheter 2103is removed, the tetherable guide-sheath 400 can be coaxially locatedover the tethering device 100. The mouth 508 of the tetherableguide-sheath 400 can be adjusted, e.g., the tetherable guide-sheath 400may be torqued, to direct the mouth 508 toward the entrance of thetarget vessel 1906, e.g., the ICA or another target vessel 1906.

At operation 2014, the tetherable guide-sheath 400 can be attached tothe tether 104 of the tethering device 100 at a point of fixation 1912proximal to the entrance of the target vessel 1906. For example, an RHV(not shown) connected to a connector of the proximal furcation 404 ofthe tetherable guide-sheath 400 can be tightened to lock the tether 104of the tethering device 100 to the tetherable guide-sheath 400.Optionally, another securement device, e.g., a tether gripper 1502incorporated in the tetherable guide-sheath 400 and/or the tetheringdevice 100, a locking element, a clamp, or another clamping device, canbe actuated to grip the tether 104 and lock the tether 104 to thetetherable guide-sheath 400. Thus, the tetherable guide-sheath 400 canbecome tethered to the deployed anchor 102 of the tethering device 100by the tether 104.

At operation 2016, a working device 802 can be advanced through aworking lumen 410 of the tetherable guide-sheath 400. For example, adelivery catheter can be advanced into the entrance of the target vessel1906 as described above. Delivery of the working device 802 can cause areaction force to be applied to the tetherable guide-sheath 400 betweenthe anchoring site and the point of fixation 1912, and the reactionforce may thus tension the tether 104 between the anchoring site and thepoint of fixation 1912. Accordingly, the anchoring delivery system canbuttress the working device 802 against back-out and/or prolapse tofacilitate delivery to a distal portion of the target vessel 1906. Theanchoring delivery system can provide dual anchoring points, forexample, at the ECA and the petrous carotid, that allows theguide-sheath to be pulled into position rather than “pushed” upstream.Further, the anchoring delivery system can allow for single operatorease of use in a rapid exchange fashion.

Referring to FIG. 32, a method of using several anchoring deliverysystems to gain access to a target vessel is illustrated in accordancewith an implementation. FIGS. 33A-33B illustrate operations of themethod illustrated in FIG. 32. Accordingly, FIGS. 32-33 are described incombination below.

The method of FIG. 32 can include operations similar to those describedabove. For example, at operation 3202, an anchor 102 of a firsttethering device 2202 can be deployed in a first anchoring vessel 2302.Referring to FIG. 33A, the first tethering device 2202 can be comparableto the tethering device 100 described above. Thus, the operationsleading up to and including operation 3202 can be similar to thoseleading up to and including operation 1802 of FIG. 28, or those leadingup to and including operation 2008 of FIG. 30. In an implementation, thefirst anchoring vessel 2302 is a vessel proximal to the anchoring vessel1904 used to reach a target vessel 1906. For example, the firstanchoring vessel 2302 can be an ipsilateral subclavian and can be usedas a stepping stone when an operator encounters challenging anatomiesand is unable to reach the preferred anchoring vessel 1904, e.g., theECA, with a preferred guidewire/catheter system “finder set”. In theevent that the operator cannot advance the finder set to the preferredanchoring vessel 1904, the finder set may instead be advanced into thefirst anchoring vessel 2302, where the anchor 102 of first tetheringdevice 2202 can be deployed to provide an anchor point for thetetherable guide-sheath 400.

At operation 3204, a tetherable guide-sheath 400 can be advanced over atether 104 of the first tethering device 2202 to position a mouth 508 ofthe tetherable guide-sheath 400 near an entrance of the a secondanchoring vessel 1904. Thus, the operations leading up to and includingoperation 3204 can be similar to those leading up to and includingoperation 1806 of FIG. 28, or leading up to and including operation 2010of FIG. 30.

At operation 3206, a second tethering device 2204 can be advancedthrough a working lumen 410 of the tetherable guide-sheath 400 into thesecond anchoring vessel 1904. That is, using the anchoring support ofthe first tethering device 2202 and the tetherable guide-sheath 400, thesecond tethering device 2204 can be advanced through a working lumen 410of the tetherable guide-sheath 400 into the second anchoring vessel1904, e.g., the ECA. The second tethering device 2204 can include asecond anchor 102 attached to a second distal end of a second tether104, and thus, can be similar in some or all respects to the firsttethering device 2202. That is, the first and second tethering devices2202, 2204 can be duplicates of the tethering device 100 describedabove. The second anchoring vessel 1904 can be similar to the targetvessel 1906 described above, in that the second anchoring vessel 1904can branch away from the first anchoring vessel 2302 (or vice versa)like the target vessel 1906 branches from the anchoring vessel 1904 inthe above description. At operation 3208, the second anchor 102 of thesecond tethering device 2204 can be deployed in the second anchoringvessel 1904.

Referring to FIG. 33B, the tetherable guide-sheath 400 can be relocatedto facilitate delivery of a working device 802 into a target vessel1906. At operation 3210, the tetherable guide-sheath 400 can be removedfrom the tether 104 of the first tethering device 2202. At operation3212, the tetherable guide-sheath 400 can be advanced over the secondtether 104 of the second tethering device 2204 to position the mouth 508of the tetherable guide-sheath 400 near a second entrance of a secondtarget vessel 1906. For example, the mouth 508 can be positioned towarda target ICA branching from the second anchoring vessel 1904, e.g., theECA. Thus, the tetherable guide-sheath 400 can be fixed to the secondtether 104 of the second tethering device 2204 to provide support to theworking device 802 as it is advanced into the target vessel 1906 in amanner similar to that described above. Accordingly, it is contemplatedthat one or more tethering devices 100 can be used to allow an operatorto make his or her way up to the target anatomy in an operation usingany anatomy proximal to the target anatomy as a preliminary anchoringsite to advance toward a preferred anchoring site nearer to the targetartery.

In some cases, the tetherable guide-sheath 400 may not be able toadvance to retrieve the anchor 102 of the tethering device 100. Forexample, after the anchor 102 of second tethering device 2204 isanchored in the second anchoring vessel 1904, the tetherableguide-sheath 400 may be unable to advance over the tether 104 of thefirst tethering device 2202 to capture the first anchor 102 in the firstanchoring vessel 2302. In this event, the anchor 102 of the firsttethering device 2202 can be detached, as described above, and thedetached anchor 102 can remain in the patient and the detached tether104 can be pulled out of the great vessels, aorta, and out of the accesssheath and/or the arteriotomy of the access site. Alternatively, aseparate catheter can be advanced over the tether 104 of the firsttethering device 2202 after the tetherable guide-sheath 400 is removedfrom the tether 104, and the separate catheter can capture and retrievethe anchor 102.

Referring to FIG. 34, a method of using several anchoring deliverysystems to gain access to a target vessel is illustrated in accordancewith an implementation. FIGS. 35A-35C illustrate operations of themethod illustrated in FIG. 34. Accordingly, FIGS. 34-35 are described incombination below.

In some anatomies, a “through-the-anchor” approach may be used to accessa target vessel 1906. For example, referring to FIG. 35A, a complexanatomy includes a “bovine” arch where the left CCA takes off from thebrachiocephalic artery instead of the aorta. At operation 3402, ananchor 102 of a first tethering device 2202 can be deployed in a firstanchoring vessel 2302, e.g., a brachiocephalic artery proximal to a leftCCA takeoff, branching from a source vessel, e.g., the AA. At operation3404, a tetherable guide-sheath 400 can be advanced over a tether 104 ofthe first tethering device 2202 within the source vessel to position amouth 508 of the tetherable guide-sheath 400 near a takeoff of the firstanchoring vessel 2302. For example, the mouth 508 can be locatedadjacent to the takeoff of the brachiocephalic artery from the AA. Atoperation 3406, a second tethering device 2204 can be advanced through aworking lumen 410 of the tetherable guide-sheath 400 and the deployedanchor 102 of the first tethering device 2202. For example, the anchor102 of the first tethering device 2202 can have a central lumen, as inthe case of an expandable cage, or expand in a manner that allows asecond tethering device 2204 to be advanced through or along thedeployed anchor 102 of the first tethering device 2202 toward a targetvessel 1906. At operation 3408, an anchor 102 of the second tetheringdevice 2204 can be deployed in a second anchoring vessel 1904 distal tothe first anchoring vessel 2302. Thus, the tethers 104 of the firsttethering device 2202 and the second tethering device 2204 may remainwithin the tetherable guide-sheath 400, e.g., in respective lumens or ina same lumen.

Referring to FIG. 35B, at operation 3410, the tetherable guide-sheath400 can be removed from the tether 104 of the first tethering device2202. Subsequently, at operation 3412, the tetherable guide-sheath 400can be advanced over the tether 104 of the second tethering device 2204to position the mouth 508 of the tetherable guide-sheath 400 near atarget vessel 1906. The tetherable guide-sheath 400 can be advanced upthe tether 104 of second tethering device 2204 to the anchoringvessel/target vessel junction, e.g., the carotid bifurcation. The mouth508 of the tetherable guide-sheath 400 can be positioned to face thetarget vessel 1906, e.g., the ICA.

Referring to FIG. 35C, if the target vessel 1906 cannot be reached, theCCA can be used as an anchor point for the second tethering device 2204to be deployed. Thus, the anchor 102 of the first tethering device 2202can be anchored in the brachiocephalic artery, and a working device 802,such as an implant delivery system, can be delivered through a workinglumen 410 of the tetherable guide-sheath 400 to traverse through theanchor 102 of the first tethering device 2202.

Referring to FIG. 36, a method of deploying an anchoring delivery systemto gain access to a target vessel is illustrated in accordance with animplementation. At operation 3602, an operator can deliver a findercatheter (typically a 5 F guide or diagnostic catheter) to an anchoringvessel in a patient anatomy, e.g., an external carotid artery (ECA). Atoperation 3604, the tethering device can be advanced through the findercatheter. The tethering device 100 can have a pusher tube 109 preloadedover a runner tube 113 of the tether 104. As the tethering device 100 isadvanced, the anchor 102 can slide through the finder catheter in anunexpanded state, constrained by the finder catheter. The tetheringdevice 100 can be advanced until the anchor 102 is near a distal end ofthe finder catheter, and near an anchoring site in the anchoring vessel1904. In some implementations, the distal joint 108 of the anchor 102can move relative to the proximal joint 108 of the anchor 102, i.e., theanchoring wire can slide within the runner tube, may allow the anchor102 to be easily loaded into a sheath or a catheter by simply pushingthe anchor 102 into the sheath. More particularly, by pushing the anchor102 into the sheath using the tether 104, the push force can betransmitted through the anchor 102 to cause the anchor 102 to elongateand/or contract such that the procedure effectively “pulls” the anchor102 into the sheath, which may significantly simplify loading.

At operation 3606, the anchor 102 can be deployed at the anchoring siteby advancing the anchor 102 out of the finder catheter, or by retractingthe finder catheter over the tethering device 100 to unsleeve the anchor102. The anchor 102 can therefore self-expand to the expanded state topress against, and anchor, within the anchoring vessel 1904. In animplementation, the anchor 102 includes a closed-cell structure, andthus, the anchor 102 can remain constricted in an unexpanded diameter aslong as the anchor 102 is not full released. This may simplify therelease of the anchor 102 into the anchoring anatomy.

Still with respect to FIG. 36, at operation 3608, after the anchor 102is anchored at the anchoring site, the pusher tube 109 can be removedfrom the tether 104. More particularly, the pusher tube 109 can bepulled proximally to slide over the runner tube 113 and to be removedfrom the patient anatomy.

At operation 3610, the operator may optionally adjust the anchor 102 toachieve a predetermined degree of anchoring. For example, the anchorwire 111 can be pulled relative to the runner tube 113 to cause adesired degree of expansion of the anchor 102. It will be noted thatthis may cause the anchor 102 to expand from a first expanded state,e.g., a self-expanded state, to a second expanded state, e.g., anactuated state. Accordingly, the second expanded state may be greaterthan the first expanded state to seat the anchor 102 in the anchoringvessel 1904. The opposite can be true, and the anchor wire 102 can beadvanced relative to the runner tube 113 to reduce the degree ofexpansion from the self-expanded state to the actuated state, e.g., ifthe operator assesses that the anchor 102 is oversized for the anchoringvessel 1904 and that a reduced expansion diameter will reduce thelikelihood of vascular trauma while still achieving effective seating ofthe anchor at the anchoring site.

At operation 3612, the finder catheter can be removed from the patientanatomy with a pulling motion. In an implementation, the anchor 102provides a resistive anchoring force greater than the friction forceapplied to the tether 104 by the finder catheter, and thus, thetethering device 100 remains in place during retraction of the findercatheter.

At operation 3614, the operator can advance the tetherable guide-sheath400 over the tether 104 of the tethering device 100. For example, theanchor wire 111 can be loaded into the tether distal port 504 of thetetherable guide-sheath 400 and the tetherable guide-sheath 400 can beadvanced over the runner tube 109 through the anatomy toward the targetvessel 1904. More particularly, the tetherable guide-sheath 400 can beadvanced until the mouth 508 is positioned at a takeoff of a targetvessel 1906, e.g., an internal carotid artery (ICA) leading to atargeted treatment location such as an aneurysm or a stenosis. Thetetherable guide-sheath 400 can be torqued to rotate the mouth 508 suchthat a working device delivered through the working lumen will bedirected into an entrance of the target vessel 1906 at the anchoringvessel/target vessel junction by the deflecting surface in the workingchannel of the tetherable guide-sheath 400.

At operation 3616, the tetherable guide-sheath 400 can be attached tothe tether 104 of the tethering device 100. For example, the tethergripper 1502, e.g., an RHV or another gripping technology (see“Dedicated Exit Lumen” and “Multi-headed RHV” implementations) can beused to affix the tetherable guide-sheath 400 to the tethering device100 at a point of fixation 1912 proximal to the anchoring site 1904and/or the entrance to the target vessel 1906.

At operation 3618, the anchor wire 111 of the tether 104 can be fixed byreleasing an RHV 434 connected to the tether proximal port 414 andpulling relative to the tetherable guide-sheath 400 and then fixing itagain in position. A locking element 130 may be added to additionallyfix the anchoring wire 111 as well as given the operator an easy“handle” with which to apply push/pull on the distal anchor 102 via theanchor wire 111.

At operation 3620, a working device, e.g., an implant delivery system,may be advanced through the working lumen into the target vessel 1906 toperform a preferred treatment. As the working device is advanced intothe target vessel 1906, any reaction force applied by the distal anatomymay be transmitted by the working device to the tetherable guide-sheath400 and the tethering device 100, placing the tether 104 in tensionbetween the anchoring site 1904 and the point of fixation 1912. Whereassuch reaction force may ordinarily cause buckling of the working device,the tetherable guide-sheath 400 may be buttressed by the tensionedtether 104, and thus, may effectively support the working device toallow it to be advanced without buckling or prolapse. Once the workingdevice is in place, e.g., at the embolus, the preferred treatment, e.g.,delivery of a stent or coil, can be performed. The working device canthen be removed from the anchoring delivery system and the patientanatomy.

At operation 3622, the tetherable guide-sheath 400 has a detachmentpoint 1916 that allows the operator to manually grasp the runner tube113 or apply a locking element 130 to the runner tube 113. Force may beapplied to the runner tube 113 to move the runner tube 113 relative tothe anchor wire 111 to collapse the anchor 102 from the expanded stateto or towards an unexpanded state, or from the actuated state to theself-expanded state. The anchor 102 can thus be withdrawn into thetether lumen 408 and/or chamber 515 of the tetherable guide-sheath 400,or the tetherable guide-sheath 400 can be exchanged with a separatecatheter, such as a guide or diagnostic catheter, that can be advancedover the anchor 102 to capture the anchor 102. The tetherableguide-sheath 400 and/or tethering device 100 can then be removed fromthe patient anatomy to complete the use of the anchoring delivery systemand finish the intervention.

Referring to FIG. 37A, a schematic view of an anchoring delivery systemdeployed in a target anatomy is illustrated in accordance with animplementation. The proximal portion of the tetherable guide-sheath 400can incorporate a multiheaded RHV 1918. The multiheaded RHV 1918 caninclude an elongated arm 1920 having a detachment point 1916 to exposethe runner tube 113 for operator access. The elongated arm 1920 mayprovide an extension leading to the tether gripper 1502, which mayinclude an anchoring RHV. For example, the anchoring RHV may include acollet, such as a brass or metal insert in the diaphragm which allows itto grasp and hold the anchoring wire, as described in more detail above.

The detachment point 1916 can include a detachable coupling, which maybe formed by numerous mechanisms. For example, the elongated arm 1920can include an external O-ring that fits within an internal grooveformed in the multi-headed RHV. The elongated arm 1920 can include arigid or semi-rigid clear extender that is of sufficient distance toreach and surpass the end of the runner tube 113. More particularly, atransition point 1922 between the anchor wire 111 and the runner tube113, i.e., a proximal end of the runner tube 113, may occur within theelongated arm 1920 when the elongated arm 1920 is attached to themulti-headed RHV body. Accordingly, the runner tube 113 and the anchorwire 111 may be visualized, e.g., if they are of different colors orsufficient contrast to each other, in the extension tube. In animplementation, the elongated arm includes demarcations that may be usedto estimate a tension applied to the tethering device 100. For example,a first distance between a point on the anchoring wire 111 and theproximal end of the transition tube may be measured when the anchor 102is in the self-expanded state, and a second distance between thosepoints may be measured upon actuation of the anchor wire 111. Adifference in the distances may correspond to a degree of tension or anamount of anchoring provided by the tethering device 100.

The detachment point 1916 may or may not have an ability to restrain orfix the runner tube 113. In an implementation, an “in-line” RHV can beused to fix the runner tube 113 at the detachment point 1916.Alternatively, a transient fixation can be achieved using a push button,a lever, or another mechanism that can be actuated by an operator totemporarily apply pressure to the runner tube 113 when desired.Transient fixation can allow withdrawal of the anchor wire 111 relativeto the runner tube 113 for adjustments during a procedure, and suchadjustments may be followed by fixation of the anchor wire 111 with aseparate anchoring RHV. If prolonged fixation is provided on the runnertube 113 and the anchor wire 111 simultaneously, the relative size ofthe anchor 102 can remain fixed by the relative positions of the tethercomponents, and the transient increase and decrease of anchoring byloads applied to the tether 104 by the tetherable guide-sheath 400,e.g., during working device advancement, may not occur.

Reiterating the steps above with the system illustrated in FIG. 37A-37B,after the tetherable guide-sheath 400 is positioned, the tether 104 canbe fed through the elongated arm 1920 of the multiheaded RHV 1918 andthe anchoring RHV 1502 can fix the anchor wire 111 as it is tightened. Alocking element 130, i.e., a torque device as is known in the art, canalso be added to provide security of the hold on the system. If therunner tube 113 has an independent fixating technology applied to it (itis not “non-restraining”), then the relationship of the runner tube 113and the anchor wire 111 can be stabilized to fix the tension applied tothe anchor 102.

Referring to FIG. 37B, a schematic view of an anchoring delivery systemdeployed in a target anatomy is illustrated in accordance with animplementation. The proximal portion of the tetherable guide-sheath 400can include a dedicated bifurcation having the multi-headed RHV 1918.For example, the working lumen may pass through an arm of the dedicatedbifurcation having length of 10 to 20 mm between the working proximalport and the bifurcation point. Accordingly, standard RHVs may beconnected to the tetherable guide-sheath 400. This “dedicated exit”version of the tetherable guide-sheath system may include the workinglumen and the tether lumen, and the tether lumen may extend through theelongated arm and the tether gripper. More particularly, each end of thededicated bifurcation may include a “single-headed” RHV. The armsections of the dedicated bifurcation may be separated, e.g., by 10 to20 mm, to avoid operator confusion during use. The working lumen portionof the dedicated bifurcation, i.e., the working lumen and RHV connectedto the working lumen, may operate similar to typical neurovascularaccess systems. The tether lumen portion of the dedicated bifurcationmay include a clear semi-rigid or rigid segment, i.e., the elongatedarm, to allow visualization of the runner tube and anchoring wire forrefined adjustment of the expansion of the anchor, as described above.The anchor wire may also be anchored outside the locking RHV with ananchoring locking element or other clamping device. Furthermore, thedetachment point may or may not have an ability to restrain or fix therunner tube in place, as described above.

Referring to FIG. 38, a schematic view of an anchoring delivery systemdeployed in a target anatomy is illustrated in accordance with animplementation. The anchor 102 can be configured anchor within a vessel1904. As previously described, anchoring can be controlled by adjustinga relative position of the anchoring wire 111 relative to the runnertube 113. In an implementation, the tethering device 100 can include alocking mechanism to fix the relative position between the anchoringwire 111 and the runner tube 113 after the desired anchor dimension ortension is achieved.

In an implementation, the locking mechanism includes a pair of clampingmechanism or devices, such as a pair of locking elements 130. Eachlocking element 130 can have a fitting adapted to grip one or more ofthe tether components (the runner tube 113 or the anchoring wire 111)securely. Thus, a predetermined tension can be applied by gripping andmoving the tether components by a respective locking element 130. Thepair of clamping devices can be referred to as an anchor wire lockingelement 130 a (connected to the anchor wire 111) and the runner tubelocking element 130 b (connected to the runner tube 113). In animplementation, the anchor wire locking element 130 a is sized to acceptthe anchor wire 111 diameter, but not to accept the larger diameter ofthe runner tube 113. For example, the anchor wire locking element 130 acan incorporate a collet having a relaxed inner diameter smaller thanthe outer diameter of the runner tube 113. By contrast, the runner tubelocking element 130 b can be sized to receive the runner tube 113 in theunclamped state, but to lock down firmly on the runner tube 113 in alocked state, e.g., when the torque device is actuated by rotation of acap component on a body component, as is known in the art.

The paradigm of a pair of locking element devices 130 to control thetethering device anchor 102 expansion can be incorporated in a“dedicated bifurcation” version of a tetherable guide-sheath 400 or in a“multiheaded RHV” version of a tetherable guide-sheath 400. In eithercase, respective locking elements 130 can be tightened down on acorresponding anchor wire 111 and a corresponding runner tube 113 toapply tension to expand or contract the anchor 102, e.g., between anunexpanded state and an expanded state. Furthermore, the locking elementdevices 130 can be gripped to advance or withdraw the tethering device100 within the tetherable guide-sheath 400, or to advance or withdrawthe combined anchoring delivery system.

In an implementation, the locking elements 130 can be used to lock theanchor 102 in position. For example, after pulling on the anchoring wire111 relative to the runner tube 113 to expand the anchor 102, theanchoring wire locking element 130 a can be repositioned to abut aproximal end of the runner tube 113. The anchoring wire locking element130 a can then be tightened and released, such that spring forceretained within the anchor 102 can tension the anchoring wire 111 andthe proximal end of the runner tube 113 can press against (but not move)the anchoring wire locking element 130 a. The tethering device 100 cantherefore be locked into position to maintain a constant size of theexpanded anchor 102. Similarly, the runner tube locking element 130 b,after being used to apply desired pressure and expansion to the anchor102, can be loosened and advanced against the proximal furcation 404 oran RHV connected to the proximal furcation 404 so as to not allow anymotion of the runner tube 113 relative to the tetherable guide-sheath400.

Referring to FIG. 39, a flowchart of a method of deploying an anchoringdelivery system is illustrated in accordance with an implementation. Themethod shall be described below with reference to FIGS. 40A-40D, whichillustrate schematic views of an anchoring delivery system deployed in atarget anatomy, in accordance with an implementation.

At operation 4102, referring to FIG. 40A, an operator can deliver afinder catheter 1908 (typically a 5 F guide or diagnostic catheter) toan anchoring vessel in a patient anatomy, e.g., an external carotidartery (ECA). At operation 4104, the tethering device 100 can beadvanced through the finder catheter 1908. The tethering device 100 caninclude an anchor 102 having a pre-shaped element like a wire that canpass through the finder catheter as described elsewhere herein. As thetethering device 100 is advanced, the anchor 102 can slide through thefinder catheter 1908 in an unexpanded state, e.g., the lower profileconfiguration shown in FIGS. 5H-5L. The tethering device 100 can beadvanced until the anchor 102 is near a distal end of the findercatheter 1908, and near an anchoring site in the anchoring vessel 1904.The anchor 102 can be pushed through the finder catheter 1908 by thepusher tube 109.

At operation 4106, referring to FIG. 40B, the anchor 102 can be deployedat the anchoring site by advancing the anchor 102 out of the findercatheter 1908, by retracting a constraining element positioned over thetethering device 100 to unsleeve the anchor 102, or otherwise deployingthe anchor 102 at the anchoring site. The anchor 102 can thereforeself-expand, e.g., to the preformed larger profile configuration shownin FIGS. 5H-5L. In the expanded state, the anchor 102 can press against,distort, and/or anchor, within the anchoring vessel 1904. In animplementation, the anchor 102 includes a coil segment having a bulbousprofile, although the anchor 102 can also include other shapes, e.g.,pigtail, bulbous, hook-shaped, conical, etc., as described herein.

At operation 4108, after the anchor 102 is anchored at the anchoringsite, the pusher tube 109 can be removed from the tether 104. Forexample, the pusher tube 109 can be retrieved from the finder catheter1908. More particularly, the pusher tube 109 can be pulled proximally toslide over the tether 104 and to be removed from the patient anatomy.

At operation 4110, the finder catheter 1908 can be removed from thepatient anatomy with a pulling motion. In an implementation, the anchor102 can provide a resistive anchoring force greater than the frictionforce applied to the tether 104 by the finder catheter 1908, and thus,the tethering device 100 remains in place during retraction of thefinder catheter 1908.

At operation 4112, referring to FIG. 40C, the operator can advance atetherable guide-sheath 400 over the tether 104 of the tethering device100. For example, the anchor wire 111 can be loaded into a tether distalport 504 of the tetherable guide-sheath 400 and the tetherableguide-sheath 400 can be advanced over the tether 104 through the anatomytoward the target vessel 1906. More particularly, the tetherableguide-sheath 400 can be advanced until a mouth 508 is positioned at ornear a takeoff of a target vessel 1906, e.g., an internal carotid artery(ICA) leading to a targeted embolus. The tetherable guide-sheath 400 canbe torqued to rotate the mouth 508 such that a working device 802delivered through the working lumen will be directed into an entrance ofthe target vessel 1906 at the anchoring vessel/target vessel junction.It should be appreciated, however, that the mouth 508 need not bealigned with or rotated towards the entrance of the target vessel 1906for the working device 802 to be delivered into the target vessel 1906.

At operation 4114, the tetherable guide-sheath 400 can be attached tothe tether 104 of the tethering device 100. For example, a tethergripper, e.g., an RHV or another gripping technology, (not shown) can beused to affix the tetherable guide-sheath 400 to the tethering device100 at a point of fixation 1912 proximal to the anchoring site and/orthe entrance to the target vessel 1906.

At operation 4116, referring to FIG. 40D, a working device 802, e.g., animplant delivery system, can be advanced through the working lumen intothe target vessel 1906 to perform a preferred treatment. As the workingdevice 802 is advanced into the target vessel 1906, any reaction forceapplied by the distal anatomy may be transmitted by the working device802 to the tetherable guide-sheath 400 and the tethering device 100,placing the tether 104 in tension between the anchoring site and thepoint of fixation 1912. Whereas such reaction force may ordinarily causebuckling of the working device 802, the tetherable guide-sheath 400 canbe buttressed by the tensioned tether 104, and thus, may effectivelysupport the working device 802 to allow it to be advanced withoutbuckling or prolapse. At operation 4118, once the working device 802 isin place, e.g., at an aneurysm or stenosis, the preferred treatment,e.g., delivery of a stent, stent-assisted coil, or flow diverter, etc.,can be performed. The working device 802 can then be removed from theanchoring delivery system and the patient anatomy.

At operation 4120, the tether 104 can be pulled to withdraw the anchor102 into the tether lumen 408 of the tetherable guide-sheath 400, or thetetherable guide-sheath 400 can be exchanged with a separate catheter,such as a guide or diagnostic catheter, that can be advanced over theanchor 102 to capture the anchor 102. The tetherable guide-sheath 400and/or tethering device 100 can then be removed from the patient anatomyto complete the use of the anchoring delivery system and finish theintervention.

Methods of Intracerebral Stent Delivery Using an Anchoring DeliverySystem

The anchoring delivery systems described herein can address many of theissues that standard neurovascular delivery systems for delivery of aflow diverter or a stent implant can create. The anchoring deliverysystems described herein can create an anchor point at a bifurcationsuch as the subclavian takeoff and advancing a working device out of thesheath tip against resistance can create a downward force on the sheath,which in conventional sheaths without anchoring would result in prolapseof the sheath into the ascending aorta. The anchor point provided by thetethering device anchor prevents prolapse and provides guide support atthe point of bifurcation. The anchor anchored in an anchoring vesselalong with the tetherable guide-sheath fixed to the tether of thetethering device at a fixation point proximal to the anchoring site,e.g. at a locking RHV of the tetherable guide-sheath can create acinching point at the ECA/ICA junction (or at another bifurcationpoint(s)) when a working device is delivered through the mouth of thetetherable guide-sheath into the target vessel thereby reducing alikelihood of prolapse into the aorta. Described below are methods ofadvancing an implant delivery system through an anchoring deliverysystem as described throughout that may replace standard approaches whenthe target site includes a target aneurysm or stenosis in the anteriorcirculation.

FIG. 41A shows an implementation of an anchoring delivery system 10having a guide-sheath 400 and a tethering device 100 with a distalanchor 102 coupled to a proximal tether 104. The anchor 102 is showndeployed within an anchoring vessel 1904 and the tether 104 of thetethering device 100 is shown locked into position at a fixation point1912 proximal to the anchoring vessel 1904 such as at a proximalhemostasis valve 434 of the tetherable guide-sheath 400. It should beappreciated that although the figures illustrate schematically theanchor 102 having a particular configuration (e.g. an expandingstent-like anchor) that the anchor configuration used in the methodsdescribed herein can vary and is not intended to be limiting. The targetlocation 925 can be an aneurysm or an embolism or stenosis located, forexample, at the M1 or M2 segments. Once deployed as shown in FIG. 41B,the anchoring delivery system 10 can provide a fixed point from which animplant delivery system 915, e.g. a SE stent delivery system, can pushoff into any obstruction that the implant delivery system may encounter.The implant delivery system 915 is shown as a self-expanding stentdelivery system that is an over-the-wire system, although it should beappreciated that other implant delivery systems and working devices areconsidered herein. The implant delivery system 915 can be inserted intothe guide-sheath 400 of the anchoring delivery system 10 and trackedover a procedural guidewire 910 extending through the working lumen 410of the tetherable guide-sheath 400 to a distal vasculature in the targetvessel 1906. The implant delivery system 915 can encounter severe turns,for example between the ICA/ECA takeoff from the aortic arch as well asother tortuous anatomy leading to the target site 925, e.g. the carotidsiphon.

FIG. 41C shows advancement of the implant delivery system 915 withforward push at the RHV 434 (point A) through the tetherableguide-sheath 400 and out the mouth 508 near the tip 406 and advancedinto the tortuous distal carotid and cerebral anatomy. A distal tip ofthe implant delivery system 915 can be guided by the course of apreviously-positioned procedural guidewire 910 and can encounter an areaof tortuosity where it meets resistance (arrows near point B) in takingthe curve 930. Further advancement of the implant delivery system 915can lead to a downward reaction force that can buckle the implantdelivery system 915 if used with a standard guiding sheath without anytethering. The tetherable guide-sheath 400, however, being tensioned bythe tether 104 and thus, resisting prolapse from the reaction force, maybuttress the implant delivery system 915 against the reaction force toprevent such buckling. Thus, anchoring at point C prevents prolapse andbuckling of the guide sheath 400 into the potential space of theascending aorta or any of the descending aorta. The anchoring can occurboth at the anchor 102 deployed in the ECA, preventing downwardmovement, as well as in the CCA proper, preventing lateral movement.

FIG. 41D shows how the anchoring provides the operator greater abilityto transmit pressure to the tip of the implant delivery system 915. Asdescribed herein, pressure applied by the operator when using aconventional sheath having no anchoring to deliver the implant deliverysystem 915 can result in more prolapse than system advancement to thedesired target 925. Continued forward advancement and ability totransmit that pressure can allow navigation of many more tortuous turnsthan would otherwise be possible with an unanchored sheath systemincreasing the likelihood of success in reaching challenging targetlesions much more consistently and more quickly.

The anchoring delivery systems described herein prevents laxity in thesupport system below the target lesion. This allows for a very directinteraction between the push-and-pull at the hands of the operator andthe fluoroscopically-guided stent placement and a more direct“one-to-one” feel. The implants are also delivered with more precisionand accuracy to the target location and with less movement. For example,the “back and forth” pistoning of the working device, e.g., a deliverymicrocatheter, can be mitigated by the support from the anchoringdelivery system 10 such that placement of Stentriever, flow diverters,stents, or other implant devices in the intracerebral anatomy is moreprecise and accurate. These types of implant devices typically areinserted into a microcatheter lumen and with a pushwire, each “bite” ofadvancement up the column of the sheath and the microcatheter can leadto a back-and-forth dislodgement and migration of the distal tip, andoccasionally loss of position. The anchoring provided by the anchoringdelivery systems 10 described herein helps a variety of interventionsincluding implant delivery.

Referring now to FIG. 42A, a support catheter 900 (also referred toherein as a “guiding catheter” or a “distal access catheter”) usedcommonly with typical sheath systems to provide support to the level ofthe petrous or other targets in the distal ICA and vertebral anatomy canbe used in conjunction with the anchoring delivery system 10 describedherein to deliver an implant 920 to an intracerebral anatomy. FIG. 42Bshows the support catheter 900 extending through the mouth 508 of thetetherable guide-sheath 400 and supporting an implant delivery system915. The implant delivery system 915 can be advanced and can encountertortuosity that creates downward and lateral forces described elsewhereherein. The tetherable guide-sheath 400 anchored by the tethering device100 can resist both the back-out into the ascending aorta and alsolateral movement of the catheter system within the ICE and the CCA.FIGS. 42C-42D show advancement (point A of FIG. 42C) of a stent deliverysystem 915 into a triaxial system that includes the support guide 900and the anchoring delivery system 10 advanced over a proceduralguidewire 910. The support provided by the anchoring delivery system 10and the support catheter 900 positioned in the body carotid can give adramatically increased ability to deliver a force to the implantdelivery system 915 at the tip to push around an obstruction and/ortortuosity (point B of FIG. 42C). Accordingly, a target site 925, e.g.,an aneurysm or stenosis, can be reached in the intracerebral anatomyfaster, more precisely, with improved accuracy, and with a reducedlikelihood of malapposition as compared to delivery without the use ofthe anchoring delivery system 10.

Self-Expanding (SE) Stent Placement

The anchoring delivery systems described herein can be used to deliver aSE stent delivery system. SE stent delivery systems generally include aself-expanding stent positioned within a constraining tube that uponproximal withdrawal allow the stent to expand within the vessel. Preciseand accurate delivery of an implant at distal sites within the cerebralvasculature can be impaired by release of stored tension within thesystem upon deployment of the implant. The anchoring delivery systemsdescribed herein can resist and/or relieve this stored tension, thattogether with the elimination of catheter system prolapse describedelsewhere herein, ultimately increases the precision and accuracy ofimplant deployment at a target location.

FIG. 43A shows a distal aneurysm target 925 as the target for deliveryof an implant, which can include any of a variety of expanding implantssuch as a flow diverter, stent, or other implant. It should beappreciated that the treatment sites described herein can include, butare not limited to aneurysm, stenosis, occlusion, or otherinterventional treatment site where delivery of an implant is desired. Aprocedural guidewire 910 can be used to direct an implant deliverysystem 915 delivered through a standard sheath 905. The standard sheath905 is shown placed in the CCA to provide support for the implantdelivery system 915. Advancement of the implant delivery system 915 canstore tension in the entire system below the tip of the implant deliverysystem 915 as the tip meets resistance at the points where the forcesare downward and lateral to the supporting catheter system and then thetip of the implant delivery system 915 passes beyond those points ofresistance. For example, as the tip navigates a straight segment of thevessel and enters a bend, an amount of tension gets stored. Upon exitingthe bend and entering another straight segment, that tension can getreleased and propel the entire system forward creating a “jump.”Referring now to FIG. 43B, the resistance can be at a tortuosity in thevessel and/or an obstruction, bifurcation, presence of a preexistingimplant, etc. The least supported catheter in the system, e.g. theimplant delivery system catheter 915 of FIG. 43B, will typically bucklethe most and to a lower degree than, for example, the sheath 905.Generally, this sort of buckling of the implant delivery system catheter915 can be visible to the operator and the operator can correct forthis. What can be more subtle is the movement of the sheath 905.Downward forces can push the sheath 905, in some cases at least 5 cm, 10cm, or 15 cm or more, down into the aorta, depending of course on thepeculiarities of each patient and how the sheaths and catheters of thesystem interact with the anatomy. When movement of the sheath 905 issevere, catheters can dislodge and loop and twist creating replacementand removal issues. Tension can also be stored without a loss ofposition.

Buckling of the implant delivery system catheter can lead to loss ofguidewire 910 position and backing out of the sheath 905 with prolapseof the catheter systems 915 into the ascending aorta AA as describedelsewhere herein. Additionally, the sheath 905 can move proximally (ordownward) due to aorta prolapse and downward pressures upon furtheradvancement of the implant delivery system 915, despite “wanting” to befurther distal (or upward) due to the stored tension (see dotted linesin FIG. 43B). The resultant effect of the stored tension, even as theimplant delivery system 915 crosses and eventually reaches the target,can be a “back-and-forth” type of movement to reach the target site 925,e.g., the aneurysm or stenosis, combined with subsequent vascular traumaand risk, as well as the steady storage of tension in the sheath 905 asit is relentlessly pushed downward (see FIGS. 43C-43D). The rhythm ofendovascular interventions is that there can be points of greaterresistance and lesser resistance on the path to the target resulting ina “staccato” movement where there may be moments of resistance to thepoint of stoppage, followed by what feels like free catheter movementupon entry of open field that helps to store incremental tension abovewhat is already stored in the sheath 905. Depending on the tortuosity,this can repeat over and over again. The latent and most problematicstored tension can be at the sheath 905. Where stored tension at thelevel of the implant delivery system 915 and buckling of the catheter900 is usually visible and can be minimized by operator manipulationsand equipment variations, stored tension and buckling at the level ofthe sheath 905 can be off the field of view under fluoroscopy. Thus,substantial movements (e.g. multi-centimeter movements) of the sheath905 that are out of the field of view or more subtle movements that arein the field of view can be missed by the operator. Alternatively, anoperator may move the patient under the image intensifier to examinerthe support system at the level of ICA, CCA, or below. Extra imagingleads to extra radiation exposure for both the operator and the patient.

The stored tension in the sheath 905 can be particularly problematicbecause it can propel the entire system forward (distally) once thepressure on the implant delivery system 915 is reversed, such as whenunsleeving a catheter from a self-expanding stent for deployment at thetarget location. FIG. 43D shows an implant delivery system 915 crossinga target 925 and ready to deploy an implant (not visible, but locatedinside the system 915) at the target location across the treatment site925, such as across a neck of an aneurysm or a length of a narrowing inthe vessel. Withdrawal of the implant delivery system 915 can releasethe self-expanding stent 920 from constraint and cause a reversal of theforce exerted on the implant delivery system 915. This can relieve orrelease the stored tension in the sheath 905 that can cause the sheath905 to “jump.” This can cause the implant delivery system 915 and theimplant 920 being deployed to miss the target site during unsheathing.This leads to inaccurate and imprecise positioning of the stent often toa point past the target location (FIG. 43E). The extreme tortuosity ofthe intracerebral vasculature, particularly around the bony structuresof the skull that can require more severe pushes in order to cross incombination with the dramatic transition in the size between the largeaorta and 1-3 mm sized target vessel can cause the stored tension andjumping effect to be even more pronounced compared to other vascularanatomies.

In contrast, the anchoring delivery systems described herein preventthis jumping effect. The anchoring delivery systems described hereinprovide a supportive point within the neck from which to build supportfor the implant delivery system 915 into distal anatomies. FIGS. 44A-44Dshow the tetherable guide-sheath 400 having a tethering device 100 withan anchor 102 anchored near the bifurcation in an anchoring vessel 1904,e.g. the ECA, and coupled to a tether 104 extending proximally from theanchor 102 into a distal port of the tetherable guide-sheath 400. Theanchor 102 provides a first point of fixation of the system at theanchoring vessel 1904 and a second point of fixation between theguide-sheath 400 and the tether 104, such as near a proximal grippingelement, creates a support system for an implant delivery system 915advanced through the guide-sheath 400. The implant delivery system 915is shown advanced from the mouth 508 of the tetherable guide-sheath 400and extending towards the target anatomy. The implant delivery system915 can encounter the same downward forces described above with respectto the untethered, conventional sheath 905. However, the forces in thetethered guide-sheath 400 can be resisted by the anchor 102 deployed inthe anchoring vessel 1904 and the proximal fixation point between thetether 104 and the sheath 400. This allows for more distal tip pressureto be imparted at the tip of the implant delivery system 915 and moreefficiently transmit forces delivered by the operator. The method ofstent delivery using the anchoring delivery system hastens delivery andadvancement of the implant, eliminates the back-and-forth motion oftypical advancement, reduces pistoning during advancement of theimplant, and provides more accurate and precise final implant placement.The method also provides as near a 1:1 relationship between movementapplied at a proximal end of the implant delivery system by an operatorand movement at the distal end of the catheter. The method and thefixation provided by the anchoring delivery system also eliminatesstored tension at the sheath level, which reduces the likelihood of thejumping effect commonly experienced in stent deployment. The method andthe “locked in” fixation provided by the anchoring delivery systemsdescribed herein also can reduce the need for checking for storedtension and buckling in the sheath using the image intensifier. Further,the tetherable guide-sheath 400 can be locked relative to the visibleanatomy such that the operator may use buckling in the implant deliverysystem 915 as a guidepost for what may be occurring in the femoralsheath without needing to perform extra checks. Further, as describedelsewhere herein, the anchoring delivery system provides for a singleoperator to deliver an implant in an easy-to-use format.

Balloon Expandable (BE) Stent Placement

The stored tension and accompanying jumping effect described above withrespect to SE stent placement is markedly reduced with BE stents. Forthis reason, BE stents are generally preferred in non-compressiblevasculature such as in the thoracic cavity and in the coronaries. BEstents are generally accepted as having a greater precision withdeployment and more accurate shorter stent length requirement andability to stay in place with deployment. However, some lesions mayrelease embolic material during balloon inflation even with very smallmovements in the backward or forward direction that. Also, BE stents maybe less forgiving because there is typically no adjustment that can bemade in their placement once the balloon has been inflated and the stentexpanded. Further, BE stents can be a challenge for use in theintracerebral circulation. BE stents tend to be more rigid and can beassociated with higher complication rates, possibly because the rigidityof the BE stents provides limited access to the tortuouscerebrovasculature. BE stents are typically unsheathed such that a “hardedge” of the transition between the balloon material and the stentpositioned over the balloon can lead to catching on birfurcations ordiseased segments during navigation of extreme tortuosity of thecerebrovasculature. For example, to reach an M1 stenosis the bonyterminal carotid segment and the “loop-the-loop” segment must benavigated.

The anchoring delivery systems described herein, at the level of thecarotid bifurcation alone or in combination with a support catheter,provides a more stable platform and allows for the delivery of a BEstent system in lieu of self-expanding stent systems, which can beproblematic due to their jumping distal to the target delivery site.

Implications for Better Stent Delivery and Support

Stored tension in procedural sheaths and the resultant “jump” upondeployment of a SE stent in the cerebral vasculature leads manyoperators to deploy SE stents having a length that far exceeds the sizeof the target to ensure optimum coverage, e.g. a diseased area, stenoticregion, or a neck of an aneurysm. However, longer stents generally leadto poor stent apposition or malapposition that increases the likelihoodof an acute thrombotic event such as acute stent thrombosis. Forexample, longer stents (e.g. greater than about 30 mm) are more likelyto cause periprocedural embolic complications compared to shorterstents. Sub-optimal stent apposition with initial deployment can occurin some instances, due to a fulcrum or another anatomic barrier thatinhibit complete expansion of the stent to the vessel wall. This canleave a potential space for thrombus formation that can lead to completethrombotic occlusion. Further, a lesion being dilated by a stent can besoft such that if the stent is not forcibly apposed to the vessel wall,the dissolution of the thrombus between the stent and the wall can alsolead to high-risk malapposition. Additionally, following stentdeployment the vessel can positively remodel leaving a potential spacefor thrombus formation.

Because of the thromboembolic risks associated with longer stents,particularly in the cerebral vasculature, due to poor stent appositionor malapposition, it would be beneficial to use shorter stents and/orstents having a length that substantially matches the length of thestenosis, embolic lesion or aneurysm being treated. For example, theanchored delivery systems described herein can allow for the delivery ofan implant that when in the high-profile configuration has alongitudinal length that substantially matches a longitudinal length ofthe diseased region being treated, for example, a length of a stenoticregion of a vessel or in the case of an aneurysm can substantially matchthe length of the neck. In some implementations, the longitudinal lengthof the implant when in the high-profile configuration can be betweenabout 1 cm and about 4 cm, or between 4 cm and about 6 cm, or betweenabout 4 cm and about 10 cm, or between about 4 cm and about 20 cm.Sizing precisely is critical to ensure efficacy and maximize safety. Assuch, the collective length the implant extends beyond the treatmenttarget (e.g. stenotic region or the neck of the aneurysm being treated)should be no more than about 1-2 mm. Using implant delivery systems andguiding sheaths known in the art result in imprecise delivery of thestents and other implants requiring the operator to choose longerlengths than are ideal to ensure efficacious coverage at the cost ofincreased risk of thrombotic complications due to excess stent lengthand increased likelihood of poor apposition. Thus, the anchored deliverysystem for deployment of the treatment device allows for the length ofthe implant to be limited to only what is needed to bridge the treatmentsite (i.e., stenotic region or neck of the aneurysm) without extendingsubstantially beyond on either side of it.

However, shorter stents, particularly those that are self-expanding, aremore difficult to deliver precisely to the target location.Higher-pressure, post-dilation in BE stenting is generally thought toprovide better stent apposition due to the high radial strength of thistype of stent compared to the shape-memory-based SE stents. Further, BEstenting can allow for the delivery of shorter stents that can bepositioned more precisely and accurately. However, as described above,BE stenting can be more difficult to deliver into the cerebral vascularcompared to SE stents.

The methods described herein include using an anchoring delivery system,with or without the support of additive catheters, for the delivery ofBE stents or SE stents to the cerebral anatomy. The methods allow formore precise stent placement along the longitudinal (and radialdimensions in the case of BE stenting), limiting the longitudinal lengthof the expanded device to substantially match the length of the targetsite, improve stent apposition, and subsequently reduce the risk ofstent thrombosis while providing equivalent or better resolution to thehemodynamic compromise of an intracranial lesion or support forstenting, stent-assisted coiling or flow diversion. The methods alsoinclude better support delivery for stenting, stent-assisted coiling orflow diversion. The methods also provide even more precise SE stentdelivery without balloon post-dilation that is enhanced due to theability to select shorter stent products due to the more precisedelivery and less “back and forth” of stent placement.

The implant delivery systems considered herein for use with the anchoreddelivery system can vary. In some implementations, the implant deliverysystem is configured to deliver a self-expanding (SE) stent. Generally,the SE system includes the stent positioned over an inner member andhaving an outer tubular member configured to maintain the SE stent inthe low-profile configuration for delivery through the guide-sheath.Upon proximal retraction of the outer tubular member, the SE stent isreleased from the constraint and allowed to expand to its high-profileconfiguration. Upon release, the inner tubular member can be withdrawnleaving the SE stent in place within the target vessel. In anotherimplementation, the SE stent is pushed through a catheter deliverysystem. In other implementations, the implant delivery system isconfigured to deliver a balloon-expanding (BE) stent. Generally, the BEsystem includes the stent positioned over an expandable balloon on theinner member. The stent can, but need not be, covered by an outertubular member or catheter.

One or more components of the implants, working devices and anchoringdelivery systems described herein may be made from a metal, metal alloy,polymer, a metal-polymer composite, ceramics, combinations thereof, andthe like, or other suitable materials. Some examples of suitable metalsand metal alloys include stainless steel, such as 304V, 304L, and 316LVstainless steel; mild steel; nickel-titanium alloy such aslinear-elastic and/or super-elastic nitinol; other nickel alloys such asnickel-chromium-molybdenum alloys (e.g., UNS: N06625 such as INCONEL®625, UNS: N06022 such as HASTELLOY® C-22®, UNS: N10276 such asHASTELLOY® C276®, other HASTELLOY® alloys, and the like), nickel-copperalloys (e.g., UNS: N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS®400, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035 such as MP35-N® and the like), nickel-molybdenum alloys (e.g.,UNS: N10665 such as HASTELLOY® ALLOY B2®), other nickel-chromium alloys,other nickel-molybdenum alloys, other nickel-cobalt alloys, othernickel-iron alloys, other nickel-copper alloys, other nickel-tungsten ortungsten alloys, and the like; cobalt-chromium alloys;cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®,PHYNOX®, and the like); platinum enriched stainless steel; titanium;combinations thereof; and the like; or any other suitable material andas described elsewhere herein.

It should be appreciated that the methods described above may be adaptedto different anatomies. For example, the ipsilateral subclavian could bea point of anchoring in order to target the ipsilateral vertebralartery. Vertebral arteries are often very tortuous and benefit fromsupport to push interventional systems through them to target anatomiesat which interventions are to be performed. For example, a tetheringdevice can be positioned distal to the takeoff of the vertebral arterywith the mouth of the tetherable guide-sheath positioned at thevertebral ostium. In instances when the vertebral arteries are verytortuous, i.e., weaving in and out of the bony openings of the vertebralcolumn, the implant delivery catheter can provide “push” to get acrossthese turns, which is particularly beneficial for rapid access to thesite of intervention. According to various implementations, theanchoring delivery system may facilitate access to all four vessels ofthe carotid/vertebral arterial circulation as well as anatomic variantssuch as the “bovine” arch discussed above. It should be appreciated thatwhere anchoring point of fixation provided by the anchoring deliverysystems described herein as being the ECA/ICA junction that otherbifurcation points are considered herein.

Implementations describe anchoring delivery systems and methods of usinganchoring delivery system to deliver working devices to targetanatomies. However, while some implementations are described withspecific regard to delivering working devices to a target vessel of aneurovascular anatomy such as a cerebral vessel, the implementations arenot so limited and certain implementations may also be applicable toother uses. For example, an anchoring delivery system as described abovemay be used to deliver working devices to a target vessel of a coronaryanatomy, to name only one possible application. It should also beappreciated that although the systems described herein are described asbeing useful for treating a particular condition or pathology, that thecondition or pathology being treated may vary and are not intended to belimiting. For example, embodiments describe methods of intracerebralstenting. However, while some embodiments are described with specificregard to delivering a stent implant to a neurovascular anatomy, theembodiments are not so limited and certain embodiments may also beapplicable to other uses. By way of example, methods may allow for thedelivery of a flow diverter or embolic coil implant, and/or to deliveran implant to another anatomy, e.g., a coronary anatomy. Furthermore,the method may allow for the delivery of retrievable stents andStentriever to target anatomies. Use of the terms “embolus,” “embolic,”“emboli,” “thrombus,” “occlusion,” etc. that relate to a target fortreatment using the devices described herein are not intended to belimiting. The terms may be used interchangeably and can include, but arenot limited to a blood clot, air bubble, small fatty deposit, or otherobject carried within the bloodstream to a distant site or formed at alocation in a vessel. The terms may be used interchangeably herein torefer to something that can cause a partial or full occlusion of bloodflow through or within the vessel.

In various implementations, description is made with reference to thefigures. However, certain implementations may be practiced without oneor more of these specific details, or in combination with other knownmethods and configurations. In the description, numerous specificdetails are set forth, such as specific configurations, dimensions, andprocesses, in order to provide a thorough understanding of theimplementations. In other instances, well-known processes andmanufacturing techniques have not been described in particular detail inorder to not unnecessarily obscure the description. Reference throughoutthis specification to “one embodiment,” “an embodiment,” “oneimplementation, “an implementation,” or the like, means that aparticular feature, structure, configuration, or characteristicdescribed is included in at least one embodiment or implementation.Thus, the appearance of the phrase “one embodiment,” “an embodiment,”“one implementation, “an implementation,” or the like, in various placesthroughout this specification are not necessarily referring to the sameembodiment or implementation. Furthermore, the particular features,structures, configurations, or characteristics may be combined in anysuitable manner in one or more implementations.

The use of relative terms throughout the description may denote arelative position or direction. For example, “distal” may indicate afirst direction away from a reference point. Similarly, “proximal” mayindicate a location in a second direction opposite to the firstdirection. However, such terms are provided to establish relative framesof reference, and are not intended to limit the use or orientation of ananchoring delivery system to a specific configuration described in thevarious implementations.

While this specification contains many specifics, these should not beconstrued as limitations on the scope of what is claimed or of what maybe claimed, but rather as descriptions of features specific toparticular embodiments. Certain features that are described in thisspecification in the context of separate embodiments can also beimplemented in combination in a single embodiment. Conversely, variousfeatures that are described in the context of a single embodiment canalso be implemented in multiple embodiments separately or in anysuitable sub-combination. Moreover, although features may be describedabove as acting in certain combinations and even initially claimed assuch, one or more features from a claimed combination can in some casesbe excised from the combination, and the claimed combination may bedirected to a sub-combination or a variation of a sub-combination.Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Only a few examples and implementations are disclosed.Variations, modifications and enhancements to the described examples andimplementations and other implementations may be made based on what isdisclosed.

In the descriptions above and in the claims, phrases such as “at leastone of” or “one or more of” may occur followed by a conjunctive list ofelements or features. The term “and/or” may also occur in a list of twoor more elements or features. Unless otherwise implicitly or explicitlycontradicted by the context in which it is used, such a phrase isintended to mean any of the listed elements or features individually orany of the recited elements or features in combination with any of theother recited elements or features. For example, the phrases “at leastone of A and B;” “one or more of A and B;” and “A and/or B” are eachintended to mean “A alone, B alone, or A and B together.” A similarinterpretation is also intended for lists including three or more items.For example, the phrases “at least one of A, B, and C;” “one or more ofA, B, and C;” and “A, B, and/or C” are each intended to mean “A alone, Balone, C alone, A and B together, A and C together, B and C together, orA and B and C together.”

Use of the term “based on,” above and in the claims is intended to mean,“based at least in part on,” such that an unrecited feature or elementis also permissible.

What is claimed is:
 1. A method of delivering an expandable implant inan intracranial vessel, the method comprising: deploying an anchor of atethering device in an anchoring vessel forming a first fixation point,wherein the tethering device has a tether extending proximally from theanchor and wherein the anchor allows blood to flow past the anchor inthe anchoring vessel when deployed; advancing a guide-sheath to alocation near the first fixation point in the anchoring vessel, theguide-sheath having at least one lumen; attaching the guide-sheath tothe tether of the tethering device forming a second fixation pointproximal to the first fixation point; delivering the implant through theat least one lumen of the guide-sheath towards a treatment site distalto the first fixation point and located within an intracranial vessel,wherein delivering the implant through the at least one lumen tensionsthe tether between the first fixation point and the second fixationpoint; and deploying the implant at the treatment site.
 2. The method ofclaim 1, wherein the implant is a balloon-expandable stent, aself-expanding stent, or a flow diverter.
 3. The method of claim 1,wherein the treatment site is an aneurysm or a stenosis.
 4. The methodof claim 1, wherein the first fixation point is formed in the anchoringvessel near a bifurcation between the anchoring vessel and a vesselleading to the treatment site.
 5. The method of claim 1, whereindeploying the anchor comprises deploying the anchor from a low profileconfiguration to a higher profile configuration.
 6. The method of claim1, wherein advancing the guide-sheath comprises advancing theguide-sheath over the tether such that the tether extends at least inpart through the at least one lumen of the guide-sheath.
 7. The methodof claim 1, wherein the guide-sheath comprises at least a second lumen,and the tether extends through at least a portion of the second lumen.8. The method of claim 1, wherein attaching the guide-sheath to thetether comprises using a tether gripper at the second point of fixationto attach the guide-sheath to the tether of the tethering device.
 9. Themethod of claim 8, wherein the tether gripper is on one or both of thetethering device and the guide-sheath.
 10. The method of claim 1,further comprising preventing prolapse of the guide-sheath duringdelivery of the implant.
 11. The method of claim 1, further comprisingresisting tension stored in the guide-sheath during delivery of theimplant.
 12. The method of claim 1, wherein the implant is aself-expanding stent and deploying the implant at the treatment sitecomprises unsheathing the self-expanding stent by withdrawing proximallya constraint.
 13. The method of claim 12, further comprising preventingthe self-expanding stent from missing the treatment site duringunsheathing.
 14. The method of claim 1, further comprising removing theanchor from the anchoring vessel; and removing the guide-sheath.
 15. Amethod of delivering an expandable implant in an intracranial vessel,the method comprising: delivering a tethering device to an anchoringvessel, wherein the tethering device includes a tether extendingproximally from an anchor; deploying the anchor of the tethering devicein the anchoring vessel forming a first fixation point, the anchorconfigured to allow at least partial blood flow through the anchoringvessel when deployed; advancing a guide-sheath over the tether of thetethering device to position an opening from the guide-sheath near anentrance of a target vessel bifurcating from the anchoring vessel;forming a second fixation point proximal to the anchoring vessel byattaching the guide-sheath to the tether; and delivering the implantthrough the guide-sheath to a treatment site distal to the anchoringvessel, wherein delivering the implant through the guide-sheath tensionsthe tether between the anchor deployed in the anchoring vessel and thesecond fixation point.
 16. The method of claim 15, wherein the tetheringdevice fixes and supports the guide-sheath for delivering the implantthrough the guide-sheath.
 17. The method of claim 15, wherein the anchoris deployed at an anchoring site in the anchoring vessel.
 18. The methodof claim 15, wherein the guide-sheath includes a lumen to receive atleast a portion of the tether.
 19. The method of claim 18, wherein theimplant is delivered through a first lumen of the guide-sheath and thetether extends at least in part through the first lumen.
 20. The methodof claim 18, wherein the implant is delivered through a first lumen ofthe guide-sheath and the tether extends at least in part through asecond lumen separate from the first lumen.
 21. The method of claim 15,wherein the implant is a balloon-expandable stent, a self-expandingstent, or a flow diverter.
 22. The method of claim 15, wherein thetreatment site is an aneurysm or a stenosis.
 23. The method of claim 15,further comprising preventing prolapse of the guide-sheath duringdelivery of the implant.
 24. The method of claim 15, further comprisingresisting tension stored in the guide-sheath during delivery of theimplant.
 25. The method of claim 15, wherein the implant is aself-expanding stent and deploying the implant at the treatment sitecomprises unsheathing the self-expanding stent by withdrawing proximallya constraint.
 26. The method of claim 25, further comprising preventingthe self-expanding stent from missing the treatment site duringunsheathing.
 27. The method of claim 15, further comprising removing theanchor from the anchoring vessel; and removing the guide-sheath.